Model 686 Arbitrary Waveform Generator

Safety

Review the following safety precautions to avoid injury and to prevent damage to this product or to any products connected to it. To avoid potential hazards, use this product only as specified. Only qualified personnel should perform service procedures.

General Safety Summary

To Avoid Fire or Personal Injury

Observe the following precautions during operation:

• Observe all terminal ratings. To avoid fire or shock hazard, observe all ratings and markings on the product. Consult the product manual for further ratings information before making connections to the product.
• Power disconnect. The power cord provides Mains disconnect.
• Do not operate without covers. Do not operate this product with covers or panels removed.
• Do not operate with suspected failures. If you suspect that there is damage to this product, have it inspected by qualified service personnel.
• Avoid exposed circuitry. Do not touch exposed connections and components when power is present.
• Do not operate in wet or damp conditions.
• Do not operate in an explosive atmosphere.
• Keep product surfaces clean and dry.
• Provide proper ventilation. Refer to the manual's installation instructions for details on installing the product so that it has proper ventilation.

Safety Requirements

This section contains information and warnings that must be observed to keep the instrument operating in a correct and safe condition. You are required to follow generally accepted safety procedures in addition to the safety precautions specified in this section.

Safety Symbols

Where the following symbols appear on the instrument's front or rear panels, or in this manual, they alert you to important safety considerations.

The following signal words appear on the instrument and in this manual:

• CAUTION. The CAUTION sign indicates a potential hazard. It calls attention to a procedure, practice, or condition which, if not followed, could possibly cause damage to equipment. If a CAUTION is indicated, do not proceed until its conditions are fully understood and met.
• WARNING. The WARNING sign indicates a potential hazard. It calls attention to a procedure, practice, or condition which, if not followed, could possibly cause bodily injury or death. If a WARNING is indicated, do not proceed until its conditions are fully understood and met.
• CAT I. Installation (Overvoltage) Category rating per EN 61010-1 safety standard and is applicable for the instrument front panel measuring terminals. CAT I rated terminals must only be connected to source circuits in which measures are taken to limit transient voltages to an appropriately low level.

Environmental Considerations

Product End-of-life Handling

Observe the following guidelines when recycling an instrument or component.

Equipment Recycling

Production of this equipment required the extraction and use of natural resources. The equipment may contain substances that could be harmful to the environment or to human health if improperly handled at the product's end of life. In order to avoid release of such substances into the environment, and to reduce the use of natural resources, we encourage you to recycle this product in an appropriate system that will ensure that most of the materials are reused or recycled appropriately.

The WEEE symbol on the product indicates that this product complies with the European Union's requirements according to Directive 2002/96/EC on waste electrical and electronic equipment (WEEE).

Preface

This manual describes the installation and operation of the Model 686 Series using the TrueArb software. Basic operations and concepts are presented in this manual.

The easy touch screen display interface lets you create waveform scenarios in only a few screen touches.

In summary, the TrueArb technology provides AWG capabilities to the instrument, where every data point stored in memory is used to generate the output signal. The software architecture makes arbitrary waves easier to manipulate and more flexible once they have been created, and it adds sequencing features to the instrument.

Package Contents

The standard Model 686 Series package includes the following:

• 686-2C / 686-4C Arbitrary Waveform Generator equipment
• 32 GB USB Pen Drive for the software recovery procedure
• Power Cord
• Performance/Calibration Certificate
• CE Certificate

Models

Recommended Options and Accessories

O = Options, A = Accessories.

Key Features

The following list describes some of the key features of the Model 686 series:

• High resolution, high sampling rate: 14 bits, 20 GS/s.
• Best output frequency vs. amplitude trade off: 10 GHz.
• 5 Vpp single ended outputs or 2 Vpp (1 Vpp single ended) differential outputs (into 50 Ohm).
• Two operating modes in the same instrument: Function Generator (AFG) and Arbitrary Waveform Generator (AWG).
• Very long memory: up to 9 GSample per channel.
• Mixed signal generation: 2/4 analog outputs plus 8/16/24/32 digital outputs.
• Simple touch screen user interface to create complex waveform scenarios in only a few screen touches.
• Large 7 inch, 1024 x 600 capacitive touch LCD.
• Touchscreen or keypad data entry.
• Windows 10 operating system.
• USB and LAN interfaces.
• 3U case size with the possibility of rack mounting.

Mechanical Characteristics

Operating Requirements

Place the instrument on a cart or bench, observing the following clearance requirements:

• Top: 0.8 in (20 mm)
• Left and right side: 5.9 in (150 mm)
• Bottom: 0.8 in (20 mm)
• Rear: 3 in (75 mm)

The instrument is intended for indoor use and should be operated in a clean, dry, nonconductive environment. Occasionally a temporary conductivity caused by condensation must be expected. This location is a typical office or home environment. Temporary condensation occurs only when the product is out of service.

Environmental Requirements

Before using this product, ensure that its operating environment is maintained within these parameters:

Power Supply Requirements

No manual voltage selection is required because the AC adapter automatically adapts to the line voltage.

Cleaning

Inspect the arbitrary waveform generator as often as operating conditions require. To clean the exterior surface, perform the following steps:

• Remove loose dust on the outside of the instrument with a lint-free cloth. Use care to avoid scratching the front panel display.
• Use a soft cloth dampened with water to clean the instrument. Use a 75% isopropyl alcohol solution as a cleaner.

Calibration

The recommended calibration interval is one year. Calibration should be performed by qualified personnel only.

Abnormal Conditions

Operate the instrument only as intended by the manufacturer.

If you suspect the instrument's protection has been impaired, disconnect the power cord and secure the instrument against any unintended operation.

The instrument's protection is likely to be impaired if, for example, the instrument shows visible damage or has been subjected to severe transport stresses.

Proper use of the instrument depends on careful reading of all instructions and labels.

Installing Your Instrument

Unpack the instrument and check that you received all items listed in the Package Contents section.

Power the Instrument On and Off and Launch the TA Application

Power On

• Insert the AC power cord into the power receptacle on the rear panel.
• Use the front-panel power button to power on the instrument.
• Wait until the system shows the Windows desktop.
• The TrueArb software starts automatically if the instrument was working in TrueArb mode at the previous power off.

Alternatively, push the TrueArb icon to launch the application from the desktop, or push the Switch App button to switch into TrueArb mode from another application.

Power Off

• Close the application in use.
• Press the front-panel power button to power off the instrument.

Protect Your Instrument from Misuse

Check Input and Output Connectors

When connecting a cable, be sure to distinguish the input connector from the output connectors to avoid making the wrong connection.

Obtaining the Latest Version Releases

The latest release of the software may not be installed on your instrument. The latest version can be found on the BNC website (berkeleynucleonics.com/downloads) in the support area.

Install the TrueArb Application

1. Download the TrueArb setup package from the BNC website and decompress it to the instrument's local disk.

2. Right-click on the “Add-AppDevPackage” file and select Run with PowerShell to start the installation.

3. When the application has been installed, press the “Enter” button to continue.

USB Pen Drive and Recovery Procedure

In case of software failure or corrupted applications, it is possible to reinstall the full factory image of the software using the 32 GB USB pen drive included in the package.

Recovery Procedure

1. Insert the recovery USB pen drive into a USB port of the instrument. If the instrument is off, press the power-on button; otherwise, restart the instrument. Check that a keyboard is correctly connected to the instrument.
2. Once the instrument has started, press the F11 button repeatedly on the keyboard during the boot process to access the boot menu (see the image below).
3. In the boot menu, select the “UEFI: USB DISK 3.0 PMAP, partition 1” choice and then press Enter.
4. Press ‘1’ on the keyboard to start the recovery procedure.
5. Enter the code “1234” to confirm the execution of the recovery procedure.
6. Once the procedure is complete, press Enter to shut down the instrument.
7. Remove the recovery USB pen drive and power on the instrument. Follow the instructions in step 2 to access the boot menu, then select the SATA SSD source. Press Enter to confirm.

Instrument Overview

Front Panel 686-2C

• 7 in (178 mm) capacitive touch screen
• Soft keyboard and rotary knob
• Single-ended analog outputs
• Trigger In and marker outputs
• Numeric keypad
• Two USB 3.0 ports and power on/off button
• Modulation inputs

Front Panel 686-4C

The front panel of the 686-4C model differs from the 686-2C in that it has twice the number of SMA analog output connectors, because each output channel has two complementary outputs (+ and -).

The touch screen functionalities and features are described in the TrueArb Application section.

• 7 in (178 mm) capacitive touch screen
• Soft keyboard and rotary knob
• Single-ended analog outputs
• Trigger In and marker outputs
• Numeric keypad
• Two USB 3.0 ports and power on/off button
• Modulation inputs

Analog Outputs

The Model 686 series instrument has 2 or 4 analog output channels. Each one is single-ended or differential, depending on the model, and the connector type is SMA.

Marker Outputs

Each Marker Out is a digital output channel that can generate programmable digital patterns synchronous to the analog outputs. Its impedance is 50 Ohm and the output voltage amplitude ranges from -0.5 V to 1.65 V into a 50 Ohm load. To set the Marker Out parameters, refer to the Marker Settings. The connector type is a standard SMA.

Trigger Inputs

The Trigger In 1/2/3/4 connectors on the front panel allow generation to be controlled by an external signal source. They have a selectable impedance of 1 kOhm or 50 Ohm. To set the trigger parameters or the Run Mode, refer to the “Trigger” section. In Continuous mode, the trigger inputs have no effect.

Soft Keyboard and Rotary Knob

Most of the buttons you use with the TrueArb application are virtual ones on the touchscreen, but a few physical buttons control basic functions such as the setting of amplitude, offset, and frequency. A physical numeric keypad is available on the front panel and can be used instead of the virtual numeric pad.

A central knob is available for fine-tuning and adjustments during on-the-fly setup operations. The rotary knob changes the value in a continuous, analog fashion. The push-button rotary knob lets you change the value increment between Coarse and Fine adjustment.

The right-arrow key moves the selected digit to the right and the left-arrow key moves the selected digit to the left. You can press the rotary knob and rotate it to the right or left to change the delta increment.

Numeric Keypad

The physical numeric keypad lets you set the parameter value and its measure unit. Once a parameter to be edited is selected by using the touch panel or the soft keyboard, each number pressed on the keypad is shown on the display. The Bksp key is provided for deleting erroneous key presses. The [+/-] key toggles the sign of the number being entered and may be pressed after terminating the entry. After the sign and the numeric portion of the desired value have been entered, pressing the multiplier button applies the parameter. The Enter button closes the virtual keyboard and applies the entered value.

When you select a parameter in the user interface, if you press a Unit Measure Range button it automatically updates the available range allowed for that parameter.

For example, if you select the Frequency parameter and press k/m, the unit measure range is kHz; if you press M/u, it is MHz; if you press G/n, it is GHz; if you press T/p, nothing happens because that range is not available for the selected parameter. If both units of a Unit Measure Range button are available for the selected parameter (for example, Mega and Micro), pressing the range button M/u switches the range accordingly between Mega and Micro.

Rear Panel 686-2C

• 4 USB 3.0 ports
• 2 Gigabit LAN ports
• 2 Audio IN/OUT
• COM Port (COM1) RS232/422/485
• COM Port (COM2) RS232/422/485
• 2 slots for removable SSD
• 1 Ref Clk In
• 1 Sync OUT connector
• 1 Sync IN connector
• DisplayPort (DP1)
• HDMI Port (HDMI1)
• D-Sub Port (VGA1)
• 1 10 MHz (100 MHz optional) Ref Clock Output
• 1 External Clock Input
• 1 Sync Clock Output

Rear Panel 686-4C

• 4 USB 3.0 ports
• 2 Gigabit LAN ports
• 2 Audio IN/OUT
• COM Port (COM1) RS232/422/485
• COM Port (COM2) RS232/422/485
• 2 slots for removable SSD
• 1 Ref Clk In
• 1 Sync OUT connector
• 1 Sync IN connector
• DisplayPort (DP1)
• HDMI Port (HDMI1)
• D-Sub Port (VGA1)
• 1 10 MHz (100 MHz optional) Ref Clock Output
• 1 External Clock Input
• 1 Sync Clock Output
• Digital Output mini-SAS HD connector: Pod A, Pod B, Pod C, and Pod D

External Modulation Input Connector

Reference Clock Input Connector

The Model 686 series can use an external clock source to generate the sampling clock frequency. This feature allows the generator to be synchronized with an external clock. The connector type is SMA.

Reference Clock Output Connector

This connector outputs the internal 10 MHz (100 MHz optional) reference clock used to synthesize the DAC sampling clock. If the clock source is internal, it produces a signal at 10 MHz (100 MHz optional). If the source is external, it is disabled. The connector type is SMA.

Digital Output Connector

The Model 686-4C series has optional 8/16/24/32-bit digital outputs, synchronized with the corresponding analog channels, that can be programmed to generate custom digital patterns. The 24/32-bit digital outputs are available only on 686-4C models and with the ‘Half Rate’ operating mode. The digital output pins have a native CML standard and the maximum update rate is 10 Gbps.

The output connector, located on the rear of the instrument, is a customized version of the Mini-SAS HD standard connector. An optional adapter cable that converts from Mini-SAS HD to SMA is available. An optional digital probe adapter is also available to convert from Mini-SAS HD LVDS to LVTTL with programmable voltage levels.

The mixed-signal generation is a powerful solution for digital designs and validation, system synchronization, and DAC/ADC tests.

External Clock Input Connector

This connector input gives the user the ability to feed a sampling clock directly to the system. This clock bypasses the internal generator clock system of the instrument. The connector type is SMA.

Sync Clock Output Connector

This connector outputs a divided clock generated from the sampling clock of the instrument. The user can choose the output frequency from a list of all the possible values. The connector type is SMA.

Sync In / Sync Out Connectors

The purpose of these connectors is to connect and synchronize multiple instruments together. Up to 4 instruments can be synchronized.

Pattern Force Jump In Connector (with 686-FSS Option only)

The 15-pin D-Sub connector input gives the user the ability to feed the Force Jump pattern through an external signal consisting of 8 pattern bits plus one for Strobe. This pattern is necessary for the Fast Sequence Switch feature (see the dedicated “Trigger” section in Device Settings).

Quick Start Guide

If you are a beginner, you can follow the steps below to generate your first waveform.

1. Connect the power cord and push the front-panel On/Off switch to turn on the instrument.
2. Press the AWG/AFG button to switch from the Simple AFG to the TrueArb application. Wait until the TrueArb application is running and ready to accept new commands.
3. Connect Output 1 of the instrument to the oscilloscope input with a cable. Select a 50 Ohm load on the oscilloscope input.
4. Touch the Settings button on the TrueArb UI to open the instrument settings window.
5. Select Dev. Settings, open the General page, and select Continuous as the Run Mode.

6. Touch the Settings button again to close the instrument settings window.
7. By default, all channels are disabled. This means that the outputs are mechanically disconnected from the load and the digital outputs are in the OFF state.
8. The waveform sequencer at the top of the application starts by default with a single entry holding a sine waveform. Touch the Add Entry button to insert a new entry into the sequencer.
9. Touch the dropdown waveform list of the second entry and change it from DC to Ramp.

10. Enable the output channels: press and hold the CH1 button at the bottom of the application so that it is no longer grayed out.
11. Touch Entry 1 and set Repetition [N] = 2, then touch Entry 2 and set Repetition [N] = 3.
12. You can change the Amplitude / Voltage High and Offset / Voltage Low for each entry.
13. Press the RUN/STOP button and check the generated waveforms on the oscilloscope. Entry 1 should be repeated two times while Entry 2 should be repeated three times.

TrueArb Application

The Model 686 series instrument includes a 7 inch (178 mm) capacitive touch screen and an easy touch user interface based on a Microsoft Windows 10 platform. You can control instrument operations using one or all of the following input methods:

• Touch screen and front-panel soft key controls.
• Keyboard and mouse.

TrueArb Touch UI

The Simple TrueArb UI is designed for touch, to drive simplicity in operating an Arbitrary Waveform Generator. It uses the modern technique found on tablets and smart phones, available on capacitive touch-screen displays.

All the important instrument controls and settings are always one touch away:

• Swipe down to change the output channel.
• Swipe left or right to navigate through the sequencer entries.
• Pinch in or out to zoom the waveform graph.
• Use the touch-friendly virtual numeric keyboard to modify parameters and enter new values on the fly.

It is sometimes necessary to create long waveform files to fully implement a DUT test. Where portions of a waveform must be repeated, the waveform sequencer can save a great deal of memory-intensive waveform programming. The Sequencer lets you define the set of waveforms that will be generated, their sequence, the number of repetitions for each waveform, and the generation conditions.

The sequencer is mainly used for two purposes:

• Output a waveform longer than the hardware memory.
• Change the output waveform quickly on a specific trigger condition.

A sequence is made of multiple entries. Each entry contains analog and digital waveforms, properly formatted.

User Interface Description

The Simple TrueArb software environment provides easy access to all instrument functionalities and parameters. The TrueArb user interface consists of four main elements:

• Sequencer Area. The sequencer contains a list of entries that you can add or remove to create your own waveform scenario. Each entry can be repeated or changed in length. The sequencer is common to all channels.
• Sequencer Toolbar. This toolbar contains the elements used to navigate, add, and remove the sequencer items, as described below.
• Waveform Area. It contains the Waveform Graph and the waveform parameters related to the selected entry.
• Command Bar. This toolbar contains elements to control the instrument operations, modify the instrument settings, and manipulate waveforms.

The display is a 7 inch (178 mm) capacitive touch screen, and it is possible to use mobile-phone style gestures:

• Swipe up or down on the Waveform Area to switch between the Output Channel 1 and Output Channel 2 pages.
• Swipe left or right on the Sequencer Area to navigate through the sequencer entries.

Sequencer Area

The sequencer starts by default with a single entry holding a sine waveform on CH1, while on the other channels a DC waveform appears (or a Take Last waveform on an auxiliary channel). Touching the Add Entry button inserts a new entry into the sequencer. By default, a DC level (or Take Last on an auxiliary channel) waveform is placed in a new entry.

You can modify the waveform of a sequencer entry by touching the waveform graph or the name of the waveform. A dropdown list opens, showing all the waveforms available in the Waveform List (predefined, parametric, or imported).

Multiple Channels View

By touching the selected sequencer item, you can display more than one channel at the same time. This gives an overall view of all the output channels and of the sequencer entries. Use a swipe up or down gesture to scroll through the channels. Touching a sequencer item again collapses the multiple-channel view back to the single-channel view.

Sequencer Area Items

Each sequencer entry contains several pieces of information:

• The index of the entry (Entry N). Each entry is numbered from 1 up to 16384.
• The name of the waveform assigned to the selected output channel in that entry. Each output channel can have a different waveform assigned to the same sequencer entry.
• The number of repetitions. Each entry can be repeated from 1 up to 4,294,967,295 times, or an infinite number of times (INF button).

Touching the selection button in the entry opens a second toolbar that lets you:

• Select all the entries.
• Deselect all the entries.
• Remove the selected entry.
• Close the toolbar.

Sequencer Toolbar

The sequencer toolbar contains several buttons to navigate and control the sequencer:

Sequencer Warnings

Warnings are shown in the sequencer toolbar when one or more channel waveforms have been assigned to an entry with a different length. The upper warning gives a general notice of this condition. Additional warnings are displayed inside the entries where the warning condition is detected.

Waveform Area

This area is divided into two main sections: the Waveform Graph area, which contains a graphical representation of the channel waveform, and the Waveform Parameters area. The Waveform Graph describes the waveform assigned to the current channel and sequencer entry:

• The shape of the waveform.
• The waveform duration and frequency.
• The waveform amplitude.
• The waveform length, in number of samples, as it was originally defined in the Waveform List.

The Waveform Parameters area is divided in two parts. The left part contains the Channel Parameters, which can be specified independently for each sequencer entry and for each output channel. The right part contains Repetitions [N] and Entry Length [N]. These two parameters are specific to the selected sequencer entry and are common to all channels in that same entry.

Amplitude [Vpp]

Defines the peak-to-peak voltage of the waveform, expressed in volts. It is the difference between the maximum value and the minimum value.

Offset [V]

Defined as (Vmax + Vmin) / 2, expressed in volts, where Vmax is the maximum level of the waveform and Vmin is the minimum level of the waveform.

Voltage High [V]

Defines the maximum level of the waveform, expressed in volts.

Voltage Low [V]

Defines the minimum level of the waveform, expressed in volts.

Pressing the Change Format button switches between the Amplitude / Offset and the Voltage High / Voltage Low parameter pairs.

Length

It is necessary to distinguish three different definitions of length:

• Waveform Length. The original total number of samples that make up the waveform, as defined in the Waveform List. This value is displayed next to the waveform name in the Waveform Area.
• Entry Length [N]. The number of samples that will be generated for the selected sequencer entry. It is common to all channels of the instrument. Its default value is defined by the Default Entry Length [N] parameter (see Sequencer Settings).
• Sub Len. [N]. The number of samples that is affected by the Resampling Strategy for the selected channel, once the Entry Length has been defined.

The entry length granularity depends on the model and on the Operating Mode:

If Sub Length is lower than the Waveform Length, the Decreasing Strategy parameter is displayed in the second tab of the Channel Parameters. You can then choose how to adapt the waveform for the single channel within the sample interval defined by the Sub Length. The available techniques are:

• Decimation. Reduces the number of samples while maintaining the waveform shape. For example, in channel 1 a Sine predefined waveform of 16384 samples is used for a generic entry. The entry length is left at its default value (16384) while the Sub Length is set to 12000 samples. With Decimation set as the Decreasing Strategy, a complete period of the waveform is displayed to fit the Sub Length interval. The period of the sinusoid is now made up of 12000 points obtained by decimating the original waveform, while the value of the last sample is held constant for the remaining 4384 samples.
• Cut tail. Cuts the tail of the waveform, reducing its size.
• Cut head. Cuts the head of the waveform, reducing its size.

If Sub Length is greater than the Waveform Length (in which case the Entry Length must also be greater), the Increasing Strategy parameter is displayed. The available techniques are:

• Interpolation. Performs a linear interpolation between the waveform samples, extending the waveform envelope across the range [0 to Sub Len.]. For example, consider a parametric Sweep waveform of 16384 samples inserted into an entry of channel 1, with the Entry Length set to 30000 and the Sub Length set to 20000 samples. With Interpolation set as the Increasing Strategy, the algorithm stretches the waveform to the value of the Sub Length, while the value of the last sample is held constant for the remaining 10000 samples.
• Return Zero. Fills the tail of the waveform with zeros until the Entry Length value is reached. In the example, the zero value is present in the last 13616 samples (30000 Entry Len. minus 16384 Waveform Len.).
• Hold Last. Holds the last value of the waveform until the Entry Length value is reached.
• Samples Duplication. Repeats the waveform samples until the Sub Length value is reached, while the value of the last sample is held constant for the remaining samples.

Delay

Specifies the delay, from sample 0 of the current entry, at which the Sub Length interval begins. It can be expressed in time (Delay [s]) or in number of samples (Delay [N]). It can be set only when the Entry Length is greater than the Waveform Length and, at the same time, the Sub Length is lower than the Entry Length.

As an example, consider a Sine waveform of 16384 samples, a Sub Length of the same value, and an Entry Length of 30000 samples, with the Delay set to 300 ns.

Repetitions

Specifies the number of repetitions of the waveform for the selected sequencer entry. The meaning of this parameter can change according to the Run Mode setting (in Advanced Mode it is replaced by the Edit Entry button).

The virtual keypad items are as follows:

1. Parameter Name and Value. This area displays the parameter name, value, and unit of measure.
2. Numeric Keypad. Contains the keys to edit the number displayed in area 1. The [+/-] key toggles the sign of the number being entered and can be pressed at the end of editing. Touch the MIN and MAX buttons to set the minimum and maximum allowed values for the selected parameter. Use the DEF button to set the default value.
3. Arrows. The left and right arrows move the cursor or select the digit position, like the arrows on the front panel. The up and down arrows modify the value.
4. Measurement Unit. After typing the numeric value, these buttons apply a different multiplier of the measurement unit. When a measurement unit is pressed, the value is applied on the fly.
5. Coarse / Fine. The Coarse/Fine button changes the granularity of the increment. You can increment or decrement the selected parameter using the up and down arrow buttons or the rotary knob on the front panel. When Fine is selected, the increment is 1 unit at the current cursor position. When Coarse is pressed, the Delta increment is displayed in the parameter area and the value changes in steps of the selected increment. You can keep the knob pressed and rotate it left or right to change the Delta Coarse increment.
6. Control Buttons. The Close button closes the virtual keypad without applying any changes to the instrument, while the Enter button confirms the changes and applies them. The Bksp (backspace) button deletes erroneous key presses, and the Delete button deletes all digits in the text box.
7. Horizontal Scrollbar. Lets you change the selected value quickly. The position specifies the value between the allowed minimum and maximum. The increment or decrement value entered with the rotary knob or the scrollbar is applied to the instrument on the fly.

Waveform Warnings

A warning is shown in the waveform graph when the channel waveform length differs from the Entry Length. The upper warning is a general notice of this condition. Additional warnings are displayed inside the entries where the condition is detected.

Status Toolbar

The Status Toolbar reports the memory usage of the instrument and the trigger-in signal behavior.

Memory Used indicator. Shows the percentage of storage memory used to store all waveforms assigned in the sequencer.

Because of this memory limitation in Full Rate Operating Mode, primary channels can be distinguished from auxiliary channels as shown in the following table:

The distinction between primary and auxiliary channels does not exist in Half Rate Operating Mode. In that case, the maximum memory that a channel can use is the same for all channels.

Aux indicator. In Full Rate Operating Mode, shows the percentage of memory used by the auxiliary channels. It can be considered as the sum of the Sub Length parameter of the specific auxiliary channel across all sequencer entries.

As an example, consider the following sequencer, where the instrument has 2 channels in Full Rate Operating Mode. For Channel 1 (the primary channel), the length of Entry 1 is 1 Gsample, as is the length of Entry 2. The memory usage indicator reports 21 percent, because about 7.6 Gsamples of storage memory remain available to add further entries. The Sub Length parameter can be kept equal to the Length value for both entries, since CH1 has up to 9.6 Gsamples of available memory.

For Channel 2 (the auxiliary channel), the number of samples of Entry 1, defined by the Sub Length parameter, is set to the maximum value (about 1 Msample). Since the Aux indicator already reaches its maximum value with Entry 1, it is no longer possible to insert a new waveform in Entry 2. During the generation of Entry 2, the output of Channel 2 reproduces the last sample of the previous entry.

Trigger Information indicator. Provides information about the trigger signal condition:

• The Trigger status LED notifies you that the instrument has received a trigger signal.
• The Waiting Trigger LED notifies you that the instrument is waiting for a trigger signal.
• The Trigger too fast LED notifies you that a trigger event has been detected, but the trigger frequency is too high and the instrument cannot be rearmed before the previous trigger event completes. In this situation, some trigger events may be lost.

Command Toolbar & Settings

This section describes the Command Toolbar and the full Settings reference for the Model 686 TrueArb Arbitrary Waveform Generator: Device Settings (general, timing, and trigger), run modes, the Advanced Run Mode and Entry Editor Table, Channel Settings for analog and digital outputs, Marker Settings, Sequencer Settings, and the remaining user interface and log options.

Command Toolbar

The Command Toolbar contains several touch buttons that control the instrument. Its layout changes depending on the model. On the 4-channel models, some buttons are located in the More menu instead of the Command Toolbar. A detailed description of each button follows.

Command Bar Buttons

More Button Menu Items

Settings

Touch the Settings button to open the page for the Device Settings, Channel Settings, Marker Settings, Sequencer Settings, and UI Settings.

Device Settings

The device settings are common to the whole instrument. They are grouped into General settings, Timing settings, and Trigger settings.

General: Operating Mode

This parameter selects the main operating mode for all channels of the instrument, between Half Rate and Full Rate mode.

In Full Rate mode you can use the maximum sampling rate, but the available storage memory on some channels is reduced. In Half Rate mode the available memory is the same on every channel, but the sampling rate is reduced.

The main characteristics of these modes are summarized in the following tables.

Full Rate

Half Rate

General: Run Mode

The Run Mode defines the sequencer execution flow.

• Continuous: when the RUN/STOP button is pressed, each waveform loops as set in the entry repetition parameter, and the entire sequence repeats circularly until the user presses the RUN/STOP button.
• Single/Burst: when the RUN/STOP button is pressed, the instrument waits for a trigger event. When the trigger event occurs, each waveform loops as set in the entry repetition parameter, and the entire sequence repeats circularly as many times as set in the Burst Count [N] parameter. Setting Burst Count [N] = 1 places the instrument in Single mode, and the sequence runs only once.
• Triggered Continuous: when the RUN/STOP button is pressed, the instrument waits for a trigger event. When the trigger event occurs, each waveform loops as set in the entry repetition parameter, and the entire sequence repeats circularly until the user presses the RUN/STOP button.
• Stepped: after the RUN/STOP button is pressed, each entry waits for a trigger event before its execution. The waveform of the entry loops as set in the entry repetition parameter. After the generation of an entry completes, the last sample of the current entry or the first sample of the next entry is held until the next trigger is received. At the end of the entire sequence, execution restarts from the first entry.
• Advanced: in this mode the execution of the sequence can be changed using conditional and unconditional jumps (the JUMP TO and GO TO features) and dynamic jumps (the PATTERN JUMP and FORCE JUMP features). Refer to the Advanced Run Mode section for detailed information.

General: Run Mode Options

• Wait Trigger On: defines the behavior of the output during the wait trigger condition in the Triggered Run Mode. If First Sample is selected, the first waveform sample of the next entry is held until the next trigger is received. If Last Sample is selected, the last waveform sample of the current entry is held until the next trigger is received.
• Jump Mode: available in Advanced Run Mode only. It defines the behavior of the output when a Jump event happens (a JUMP TO, PATTERN JUMP, or FORCE JUMP event). If Jump as soon as possible is selected, the sequencer jumps to the selected entry as soon as possible, without waiting for the completion of the repetitions of the current waveform execution. It always jumps at the end of a period of the current waveform. If Jump when all repetitions have been executed is selected, the sequencer jumps to the selected entry after the completion of the current waveform repetitions. If the repetitions are infinite, this option is not considered and the instrument performs the jump as soon as possible.

Advanced Run Mode

The Advanced Run Mode changes the execution of the sequence using loops, conditional and unconditional jumps (the JUMP TO and GO TO features), and dynamic jumps (the PATTERN JUMP and FORCE JUMP features). It can be used to create long and complex waveform scenarios.

Follow these steps to start working with the Advanced Mode:

• In the Device Settings, General page, select Advanced as the Run Mode.
• The sequencer page changes its standard layout, and the Edit Entry button appears in the Entry Parameters area.
• Press the Edit Entry button on the Sequencer Area to open the Entry Editor Table.

Entry Editor Table

Pressing the Edit Entry button opens the Entry Editor Table. This table changes all the parameters associated with the sequencer entries (except the Length of the entries, which is still located in the Sequencer Area page) that control the execution flow of the sequencer.

Use a swipe up or down gesture to scroll through the table elements and reach the parameters of every sequencer entry.

The first column in the Entry Editor Table displays the Entry number, which defines its position in the play sequence. These numbers are also used as the targets for the Jump To, Pattern Jump, and Go To features. The selected entry is highlighted in yellow.

The Entry Editor Table has the following options.

Entry Table Toolbar

As an example, the following entry can be represented by a flow chart. Entry 1: Wait Event = Button, Repeat = 10, Jump If Event = Timer, Jump to Entry = Next, Pattern Jump = 123, Pattern To Entry = 4, Go To Entry = 3.

Jump to Selected Button

In Advanced Run Mode, the Jump To Selected button appears on the Sequencer Toolbar after the start of generation. While the instrument is generating and the execution flow is not in a Wait Event state, pressing this button forces generation to jump to the entry highlighted in the sequencer. The execution flow can jump immediately or when all the repetitions have been executed, as selected in the Jump Mode field (Device Settings, General section).

As an example, consider a sequencer where entry 18 is highlighted, with the following table entry for entry 1: Wait Event = Button, Repeat = 10000, Jump If Event = Ext. Trig. 1, Jump to Entry = Next, Go To Entry = 5.

Timing

• Sampling Clock [Hz]: specifies the Arbitrary Waveform Generator sampling rate.
• Clock Source: specifies the clock source as Internal, Reference Clock In, or External Clock In.
  • If Internal Clock is selected, the sampling clock is synthesized using a 10 MHz reference clock generated internally.
  • If Reference Clock In is selected, the sampling clock is synthesized using the clock provided externally to the Ref. Clock In SMA connector. In this case the Reference Clock [Hz] control appears, and the user must specify the reference clock frequency in Hz.
  • If External Clock In is selected, the internal clock synthesizer is bypassed and the clock signal provided at the External Clock Input SMA connector feeds the sampling clock directly for the system. In this case the External Clock In Divisor control appears to define the external clock signal frequency, which must match the value reported by the Ext. Clock Frequency indicator.

• Sync Output: enables or disables the external Sync Clock Output. This clock can be used to provide a trigger input signal synchronous with the system clock, which avoids jitter in the Trigger In to analog Out delay and reduces the Trigger In to analog Out latency. See the Trigger settings (in the Device Settings paragraph) for more details. When the Sync Output is enabled, the Sync Output Divisor parameter appears and the user can choose the Sync Output clock frequency from a list of all possible values.

Trigger

The Trigger Source specifies the source of the trigger: Trigger Input 1 (In 1), Timer, or Trigger Button.

The 686-2C models have two independent external Trigger Inputs (Trigger In 1 and Trigger In 2), while the 686-4C models have four independent external Trigger Inputs (Trigger In 1, Trigger In 2, Trigger In 3, and Trigger In 4), each located on the front panel of the instrument.

The Source and Timer Interval [s] parameters are common to all channels of the instrument. The Threshold, Edge, Input Impedance, Timing, and Delay Adjust parameters are specific to each Trigger Input. You can switch between the two or four sets of these parameters by selecting the Trigger Input 1 ... Trigger Input 4 tabs located in the middle of the Trigger Settings page.

External Force Jump Settings (with 686-FSS option only)

If the Fast Sequence Switch option is available, in Advanced mode it is possible to provide a Force Jump action by applying an external 8-bit digital signal through the Ext. Pattern Force Jump In connector on the rear panel.

In this way it is possible to set up to 256 possible patterns that force the generation to jump into one of the 16384 possible entries of the sequencer, regardless of the state of the execution flow (except the Wait Event state).

For every External Force Jump pattern, a Strobe signal with a rising or falling edge (selectable) is required to sample the digital pattern. The external digital signal must remain valid and unchanged during the entire edge of the Strobe, with the setup and hold time specified in the instrument documentation.

In the Trigger Settings page, the new Force Jump Settings tab appears beside the Trigger Input 1/2/3/4 tabs. A table representing all 256 possible pattern inputs allows you to specify which entry to jump to once an external pattern is received.

Channel Settings

The Channel Settings page defines the parameters of the analog and digital channels. The digital channel outputs are available only on the 686-4C models.

Main Settings Page (CH1, CH2, ... CH N)

• Amplitude Scale [%]: can be modified at run time to adjust the waveform amplitude while the instrument is running. It is applied to all the waveforms contained in the sequencer for the specified channel. It is expressed as a percentage and has a range of 0% to 100%. A value of 100% means the waveform keeps its original amplitude.
• Channel Skew:
  • Skew [s]: defines a time delay among the analog output channels to de-skew the outputs. The resolution is 100 fs on 2-channel models and one sampling clock period on 4-channel output models.
  • Chan. 1/3 (or 2/4) Fine Skew [s]: available only on the 4-channel models. It defines a fine time delay between the output couple Channel 1 / Channel 3 and the output couple Channel 2 / Channel 4. The resolution is 100 fs. The relationship between channels considers the Skew parameter (Nx, where x is the channel), the Chan. Fine Skew parameter (delta t13 or delta t24), and the Sampling Clock Period (Ts).
• Baseline Offset Settings:
  • Base Line Offset [V] (or Vocm [V] on the differential output models): defines the DC offset value added to the output signal relative to the ground level.
  • Value On Stop [Disabled/Custom]: this toggle selector enables the value of the Stopped Voltage Value, which is set in the stop condition. When the toggle is set to Disabled, in the stop condition the baseline value on the output follows the value set in the Baseline Offset parameter.
  • Stopped Output Voltage [V]: sets the value of the Baseline Offset in the stop condition (if the Value On Stop selector is set to Custom).
• Channel Value on Stop Settings:
  • Value on Stop [Keep Last/Custom]: selects the value generated after the stop event. Keep Last: the generator keeps the last value generated before the stop. Custom: the generator keeps a user-defined value (Stopped Output Voltage).
  • Stopped Output Voltage [V]: defines the custom value generated after the stop event.
• Polarity: when Negative is selected, the analog output signal is inverted.

Correction and Optimization (CH1, CH2, ... CH N)

• Correction Offset [V]: defines the digital offset value added to the generated waveform. The minimum value is 0 V, while the maximum value is adjusted dynamically based on the amplitude chosen for the respective waveform. For example, on the single-ended models, if the amplitude is set to 2 Vpp, the user can add a correction offset up to 1.5 V.
• Optimization: every digital-to-analog converter is affected by a series of systematic errors (INL, DNL, timing errors) that give rise to nonlinearity in the spectrum of the generated output signal. Setting High Linearity Mode reduces the noise spectral density of the output signals for better linearity, while Low Noise Mode reduces noise when the generated signal has a low frequency or consists of constant components.
• Overshoot Tuning: in an impulsive waveform, allows you to vary the amplitude of the transient value of the signal with respect to its constant value. The higher the overshoot value, the faster the edge of the output signal.
• Flatness Compensation: in RF signal generators, as the frequency increases, flatness compensation filters help limit the degradation of the amplitude of the generated signal. If you prefer better spectral purity by limiting the contribution of spurious emissions, it is better to deactivate this compensation.

Digital Channels

By purchasing the appropriate option license, it is possible to enable up to 32 digital output channels on the 4-channel models. The maximum number of digital outputs available depends on the setting of the Operating Mode parameter and the instrument model, as summarized in the following table.

• Digital Channels: if this parameter is 0, the DIG button is disabled. If 8 or more digital channels are selected, the DIG button can be touched to enable or disable the digital output lines. Once the digital channels are enabled, you can define the digital waveform in the Waveform Graph area in the same way as for analog channels. All digital lines are displayed simultaneously on the Waveform Graph via a bus composed of digital waveforms (DIG 0, DIG 1, DIG 2, and so on). The Increasing/Decreasing Strategy, Sub Length, and Delay parameters are present for each sequencer entry on the digital outputs as well.

Up to 4 Pods (a group of 8 digital outputs) can be managed separately from each other. The correspondence between Pods and digital outputs is as follows.

• AT_DTTL8 only:
  • Voltage Level [V]: defines the output voltage level (in volts) of the LVTTL digital probe. It takes effect only when the Digital Option (686-DIG license) is installed and the LVTTL probe adapter is connected (RIDER-MINI-SAS-HD and AT-DTTL8 accessories). The same voltage level applies to all 8 channels of the same Pod. For more information on the accessories, see Appendix A.
• CML Settings:
  • Diff. Voltage Level: the differential voltage level of all CML signals of the specified Pod that come from the mini-SAS HD connector on the rear of the instrument. Up to 4 values are available. All eight CML pairs of a single Pod can be more conveniently used through the SMA connectors of the AT-LVDS-SMA8 cable (see Appendix A).
  • Equalization Factor [N]: as this parameter increases, the rising edge of all CML output signals of the specified Pod and their overshoot are emphasized. Up to 16 values are available: 0 to 15.
• Skew [s]: sets the delay between the analog channels and the digital channels to de-skew the analog and digital outputs. The maximum time skew allowed depends on the current sampling frequency. The same skew applies to all 8 channels of the same Pod.

Marker Settings

In the marker output page, you can define the behavior and parameters of the Marker Out signals located on the front panel of the instruments.

The 686-2C models have two Marker Outs: Marker Out 1 and Marker Out 2. The 686-4C models have four Marker Outs: Marker Out 1, Marker Out 2, Marker Out 3, and Marker Out 4.

Each Marker Output can be programmed individually to generate a fixed level (Low or High), an automatic impulse of a fixed duration, or a completely custom digital pattern. The custom digital patterns are generated synchronously with the analog outputs and at the same update rate.

Each Marker Out has its own set of parameters. You can switch among these sets by selecting the Marker Out 1 ... Marker Out 4 icons located on the left side of the Marker Settings page.

Marker Mode

• Automatic: the marker behavior depends on the Run Mode.
  • Continuous: the instrument generates a Marker pulse of 36 sampling clock periods in Full Rate mode (or 18 sampling clock periods in Half Rate mode), synchronous with the analog outputs, for each sequencer entry and for each repetition.
  • Single/Burst: each time a trigger event is received while the instrument is waiting for a trigger event, a Marker pulse of 36 sampling clock periods is generated.
  • Triggered Continuous: at the start event, the instrument generates a Marker pulse of 36 sampling clock periods.
  • Stepped: each time a trigger event is received while the instrument is waiting for a trigger event, a Marker pulse of 36 sampling clock periods is generated. If an entry with infinite repetitions is being executed and a trigger event occurs, a Marker pulse is generated and the execution skips to the next entry. In this case the Marker pulse may not be synchronous with the waveform of the next entry.
  • Advanced: each time a trigger event is received while the instrument is waiting for a trigger event, a Marker pulse of 36 sampling clock periods is generated. The marker pulse is also generated each time a Jump event occurs; in this case it may not be synchronous with the output waveform.
• Fixed To Low Voltage / Fixed To High Voltage: the marker level is fixed to the low level or high level.
• Custom Pattern: the Marker Out generates a custom digital pattern synchronous with the analog outputs and at the same update rate. The custom pattern is defined in the same way as the digital patterns, by selecting a digital waveform in the Waveform Graph area.

In all other Operating Mode options, as well as on models where this parameter does not exist, the Custom Pattern option is always present on all available Marker Outs.

Marker Skew [s]

Defines the skew between the marker and the analog channels. The maximum time skew allowed depends on the current sampling frequency. The edited value is automatically rounded to the closest value that the hardware can implement.

High Voltage Level [V]

Sets the marker high level voltage.

Low Voltage Level [V]

Sets the marker low level voltage.

When the Marker Mode parameter is set to Custom Pattern, the user must press the MAR button until it turns pink to allow the marker signal to reach the output of its connector. All the other modes are active immediately once set. You can define the Marker Output waveform in the Waveform Graph area in the same way as for the analog channels or digital channels.

Sequencer Settings

The Sequencer Settings page contains parameters that define the strategy used to manage the length of the sequencer entries in relationship with the length of the channel waveforms defined for each entry.

Entry Length Strategy

• Adapt to the longer analog waveform: when selected, the length of an entry defaults to the length of the longest waveform among all analog channels assigned to the entry.

  Example: Entry 1 consists of two waveforms (2-channel model): the predefined SINE waveform for Channel 1 (16384 samples) and the imported sinc_100ksamples waveform (100000 samples) for Channel 2. With Adapt to the longer analog waveform selected, the Length of Entry 1 is 100000. You can manage the shape of the SINE waveform with the Sample Increasing Strategy option, for example Return Zero or Interpolation.

• Adapt to the shorter analog waveform: when selected, the length of a sequencer entry defaults to the length of the shortest channel waveform among all analog channels assigned to the entry.

  Example: Entry 1 consists of two waveforms (2-channel model): the parametric Sinc_1ksamples waveform for Channel 1 (1152 samples) and the predefined SINE waveform (16384 samples) for Channel 2. With Adapt to the shorter analog waveform selected, the Length of Entry 1 is 1152. You can manage the shape of the SINE waveform with the Sample Decreasing Strategy option, for example Cut Tail or Decimation.

• Apply the default value: when selected, the length of a sequencer entry defaults to the value specified in the Sequencer Item Default Length [N] parameter.

Waveform Length Strategy

This strategy applies only to imported waveforms where the sampling rate information of the original file is defined, such as .trc files and waveform files imported from or created in the Waveform Editor.

• Use the original waveform duration if possible: when the sampling frequency of the imported or created waveform differs from the Sampling Clock of the instrument set to reproduce it, the waveform duration during generation is no longer consistent with the original. When this option is selected, the length of the entry is automatically calculated to match the original duration of the imported waveform. For example, you can play back waveforms from an oscilloscope acquisition (.trc files only) while preserving their original duration. You can use the original waveform duration only if the imported waveform data contains the sampling rate information, such as .trc files and waveforms created using the Waveform Editor.

  Example: Entry 1 consists of two waveforms (2-channel model): the imported sweep_10k_2G waveform for Channel 1 (sampling rate of 2 GHz, 10000 samples in length, original duration 5 us) and the predefined SINE waveform (16384 samples) for Channel 2. If Use the original waveform duration if possible is selected and the Sampling Clock parameter is set to 10 GHz, the Length of Entry 1 is automatically recalculated to keep the same duration as the imported waveform, so Length [N] is 50000; the constituent samples are interpolated to maintain the shape.

• Use the waveform length: when selected, the length of the entry equals the imported waveform length in samples. In this case the original duration of the imported waveform is not maintained.

  Example: using the previous example as a reference, selecting this option keeps Channel 1 at the imported waveform length (10000). Make sure the Entry Length Strategy parameter is set to Adapt to the shorter analog waveform, because that count (10000) is smaller than the length of the waveform used for Channel 2 (16384).

Default Resampling Strategy

This defines the default setting of the resampling strategy parameter. Whenever a new entry is added to the sequencer and the Sub Length value of a channel differs from the Waveform Length value, the Increasing and Decreasing Strategy parameters of the specific channel are automatically set to their default values.

The Default Sample Increasing Strategy parameter defines the strategy used to adapt the waveform envelope when the original waveform length is shorter than the value specified by the Sub Length parameter. The available techniques are:

• Interpolation: performs a linear interpolation between the waveform samples.
• Return Zero: fills the tail of the waveform with zeros.
• Hold Last: holds the last value of the waveform.
• Samples Duplication: repeats the waveform samples.

The Default Sample Decreasing Strategy parameter defines the strategy used to adapt the waveform envelope when the original waveform length is greater than the Sub Length parameter. The available techniques are:

• Decimation: reduces the number of samples while maintaining the waveform shape.
• Cut Tail: cuts the tail of the waveform, reducing its size.
• Cut Head: cuts the head of the waveform, reducing its size.

Default Entry Length [N]

Specifies the length of the sequencer entries when the Sequencer Item Length Strategy parameter is set to Apply the default value.

Warnings Management

This parameter enables or disables the warnings shown in the Sequencer Toolbar and in the Waveform Area that notify you when one or more channel waveforms have been assigned to an entry with a different length. This situation causes the application to modify the mismatching waveforms during execution to match the entry length, using the strategy specified in the Sample Increasing/Decreasing Strategy parameter.

When the Consider a warning as an error option is selected, the application checks whether one or more sequencer entries have a length that differs from the selected waveform length. If this condition is met, the instrument does not start.

Other Settings

The Other Settings page contains parameters that set some user interface (UI) configurable parameters and the generation of a log file.

UI Setting: ON/OFF Waiting Time [s]

Sets how long the user must hold down the Channel button to turn the channel output ON or OFF. This feature is also available for the Marker button (MAR button), but only if the user has set Custom Mode as the Marker Mode in the Marker Settings. The range of the ON/OFF Waiting Time is 0 s to 2 s. The default value is 200 ms.

Log Settings

Waveform List

The Waveform List consists of three main elements:

• Shortcuts: in this area you can access a range of options dedicated to managing the waveform list.
• Graph Area: this area displays a graphical rendition of the currently selected waveform.
• Waveform List: in this area you can scroll between all stored waveforms.

The Model 686 series contains by default a set of Factory Predefined Waveforms that are common to all configurations.

Predefined Waveforms carry an orange underline beneath their names, Imported Waveforms carry a blue underline, and Parametric Waveforms carry a green underline.

The Waveform Graph

The Graph Area presents a rendition of the currently selected waveform. You can zoom in both directions with a pinch-in or pinch-out gesture, or by holding the left mouse button while dragging the pointer over the section you want to zoom. Doing so highlights the selected section with a red overlay, as shown in the following image.

To zoom out while using a mouse, drag the red slider. Among the various items of information, the area also contains a Reset Zoom button. Holding the right mouse button brings up a small shortcut menu, with options for zooming in and out and one for resetting the zoom level to default. You can also reach this menu by holding down when operating via touch, as shown below.

How to Import an Analog or Digital Waveform from a File

The Import button allows you to import data from a file to create a new waveform. The supported file formats are:

• .txt – New line (\n) separated text file (one column only, with no header).
• .zip – Compressed file in a binary proprietary format.
• .trc – LeCroy oscilloscope binary file format.
• .bin – Binary file. If the file is loaded as an analog waveform, the software uses two bytes for each sample (little-endian format). If it is loaded as a digital waveform, the software uses four bytes for each sample (little-endian format).

1. Press the Wave button located at the left end of the Shortcuts area, then press the Import button. A Windows File Browser opens. Select the .txt or .zip file you want to import, then the Import page opens.
2. In the Import dialog, the Name and Description fields are automatically filled with default values.
3. Select the Waveform Type you want to import ("Analog" or "Digital").
   • If "Analog" is selected, the waveform data is interpreted as a single column of values (a header is not allowed). The imported waveform is normalized so the user can easily adjust its amplitude and offset using the Waveform parameters in the Graph area of the sequencer.
   • If "Digital" is selected, each data point is represented by a 32-bit unsigned integer where the value of each bit is transferred to the corresponding digital line (Bit 0 maps to Digital Line 0, Bit 1 maps to Digital Line 1, and so on).
4. Press OK to confirm, or Close to cancel the operation.

How to Export an Analog or Digital Waveform to a File

• Select an analog or digital waveform in the waveform list.
• Press the Wave button and then the Export button.
• The exported waveform is stored in a proprietary binary .zip file format that can be shared with other instruments running the same application.
• You can also export the Predefined waveforms.

How to Promote an Analog or Digital Waveform to a Predefined

• Select an imported analog or digital waveform in the waveform list.
• Press the Wave button and then the Promote button.

The waveform appears in the list in red color to show that it has been promoted to Predefined.

How to Edit an Analog or Digital Waveform

• Prerequisite: the "Waveform Editor" software is installed.
• Select an analog or digital non-parametric waveform in the waveform list.
• Press the Edit button to launch the "Waveform Editor".
• Refer to the "Waveform Editor" user manual for a complete explanation of editing and creating waveforms.

How to Create a New Analog or Digital Waveform

• Prerequisite: the "Waveform Editor" software is installed.
• Press the Create button in the More... menu to launch the "Waveform Editor".
• Refer to the "Waveform Editor" user manual for a complete explanation of editing and creating waveforms.

Parametric Waveforms

Parametric waveforms simplify and speed up the process of creating custom waveforms. While the Berkeley Nucleonics Waveform Editor is still available, parametric waveforms introduce a set of highly customizable, ready-to-use waveforms that remain part of the TrueArb software.

How to Create a New Parametric Waveform

1. Press the Wave button located at the left end of the Shortcuts area, then press the New Parametric button to start the creation process.
2. In the Add Parametric Waveform dialog, the Name and Description fields are automatically filled with default values.
3. Select Predefined if you want the new waveform to be predefined.
4. Press the Add Waveform button to complete the creation process, adding the newly created waveform to the waveform list. The newly created parametric waveform is a sine waveform by default, which can later be changed to other kinds of waveform.

Parametric Waveform Types

Once a new parametric waveform has been created, its editing page opens. From here you can select different types of waveform from the Type drop-down menu. The available types are listed below.

Once you have decided which waveform type you want, you can start customizing it to suit your needs. To do so, set the characteristic parameters of the waveform type, which are accessed by scrolling up and down the waveform parameters area as shown in the following image.

The Optimized Length For Parameter

Once you have established which type of waveform to create, you can act on its parameters to specify, for example, its Frequency. The values of the other parameters, such as the Length and number of Cycles, are then automatically calculated to fit the specified frequency, also taking the value of the Sampling Clock into consideration.

In addition, keep in mind that the Operating Mode (see Dev. Settings, General page) sets not only the maximum value of the instrument's sampling clock but also the maximum available length and the granularity with which a waveform can be created.

In light of this, it is possible to understand how the parametric waveform being created is optimized for a specific Operating Mode.

Once a parametric waveform is created, changing the Operating Mode means its characteristics, such as Frequency, are no longer respected. A warning appears to report this condition, and the user, by acting on the Optimized Length For parameter, can choose whether or not to optimize the waveform for the new Operating Mode.

The Auto Calc Menu

As shown in the table of waveform types (see Parametric Waveform Types), some types, such as Pulse, Square, and Sine, have Auto Calc.

Auto Calc lifts you from the time-consuming task of finding a setup that correctly synthesizes the desired frequency. There are four strategies, with varying degrees of freedom, detailed in the following table.

Each "Free" in the table means you can change that parameter within reasonable boundaries, such as those specified by Shannon's theorem, while "Automatic" means that a parameter or pair of parameters is determined automatically and is not directly customizable.

To change the strategy in use, tap the Auto Calc Options drop-down button and select the strategy that best suits your needs from the submenu.

It is important to note the impact of the Wrap Around toggle switch. When on, it enforces a whole number of cycles. When off, the number of cycles can be non-whole. This is important and impactful while the Auto Calc Cycles or Auto Calc Cycles and Length strategies are in use, as it can lead to very different results. It comes with a drawback, though, because a non-whole number of cycles can lead to undesired signal behavior, such as a spurious signal once analyzed in the frequency domain.

The Setup Warning Menu

The Setup Warning is a feature of those waveform types that have Auto Calc, such as Pulse, Sine, and Square.

Sometimes the set of values assigned to parameters in the Auto Calc domain, which are Frequency, Sampling Rate, Length, and Cycles, leads to an unfeasible setup. This is highlighted by the Setup Warning message, which appears as soon as the condition arises. Tapping the Setup Warning message opens a small pop-up with a brief description of what is happening.

The pop-up may also offer suggestions for those same parameters, so that the user-set output frequency is correctly synthesized, as shown in the image below. You can apply those values directly from within the pop-up message, or note them down and enter them manually.

Pulse Type Parametric Waveform

Once you select Pulse from the list of available waveform types and set it up to have the desired frequency, you can start customizing it. A Pulse parametric waveform offers the following parameters related to the shape of a pulse: Fall Time, Rise Time, Pulse Delay, and one of Duty Cycle or Pulse Width. You can switch between Duty Cycle and Pulse Width at any time by tapping on them.

Both Rise and Fall times follow the 10 to 90 format and are taken into account so that the model holds true. With Pulse Delay you can control the initial delay you want your pulse to have.

Square Type Parametric Waveform

Square type parametric waveforms are closely related to Pulse type parametric waveforms, sharing all parameters except Pulse Width / Duty Cycle, which is not available. These differences arise from the fact that a Square waveform always has a 50 percent duty cycle.

Sweep Type Parametric Waveform

The Sweep type parametric waveform is one of the types that does not have Auto Calc, so you are free to customize both Length and Sampling Rate. It has three characteristic parameters: Start Frequency, Stop Frequency, and Sweep Mode. While Start and Stop Frequency are straightforward, Sweep Mode lets you change between a Linear and a Logarithmic sweep. To change the Sweep Mode, tap the Sweep Mode toggle switch.

Exponential Type Parametric Waveform

The Exponential type parametric waveform is one of the types that does not have Auto Calc, so you are free to customize Length, Sampling Rate, and Cycles. It has two characteristic parameters: Time Constant and Exponential Mode. By interacting with the Exponential Mode toggle switch, you can toggle between an Exponential Rise and an Exponential Decay.

Sine Type Parametric Waveform

Sine type parametric waveforms have Auto Calc, so once you have set the frequency you want, you can change the Phase by customizing the Phase constant among the available parameters.

Sinc Type Parametric Waveform

Sinc type parametric waveforms do not have Auto Calc, so you are free to customize both Length and Sampling Rate as you see fit. You can further customize the shape by changing one or both of the Peak Position and Lobe Width.

PRBS Type Parametric Waveform

PRBS type parametric waveforms do not have Auto Calc, leaving you free to customize Length and Sampling Rate as you see fit. You can change the PRBS type by tapping the PRBS Type drop-down menu and selecting one of the available types, as shown in the image below.

The available PRBS types are PRBS 7, PRBS 9, PRBS 11, PRBS 15, PRBS 23, and PRBS 31.

Multitone Type Parametric Waveform

Multitone type parametric waveforms let you create a custom sum of different sinusoidal tones, with a maximum of 10 tones, or fewer if the number of samples exceeds the memory limit.

Once you have set the Sampling Rate as you see fit, you can start adding your desired tones. To add a tone, tap the Add New Tone button. A dialog box opens, and within it you can set the characteristic parameters of a tone: Frequency, Amplitude, and Phase.

This kind of waveform does not have Auto Calc, yet it works in a similar fashion to the Length and Cycles option that the Auto Calc-powered waveforms have. The Length parameter, while still displayed, is not directly customizable; it is determined each time you add or remove a tone.

Once you have finished adding your set of tones, you can further customize their Amplitude and Phase on a tone-by-tone basis by interacting with each tone card in the tone queue.

You cannot change the Tone Frequency. As soon as a single tone is present in the tone queue, trying to alter the Sampling Rate results in a warning message, prompting you either to dismiss the change or to delete all queued tones before changing the Sampling Rate.

While adding a tone, you may misenter its frequency. To delete a tone you can follow two routes:

• The first simply requires you to tap the delete button on each tone card in the tone queue.
• The second, while fundamentally working like the first, is more tailored toward deleting multiple tones at once. Tap the Delete Tones button. A submenu opens, showing a brief summary of the currently queued tones. Each entry has a small checkbox you can mark to delete that tone once you tap the Delete button, as shown in the image below.

How to Create and Load a Restore Point

Once you finish setting up a parametric waveform, you can create a Restore Point. A restore point takes a snapshot of the current parametric waveform configuration, so that if you modify it, perhaps unknowingly, or you are not satisfied with the result of your changes, you only need to tap the Load Restore Point button to go back. To create a Restore Point, tap the Create Restore Point button.

How to Obtain the Array Points from a Parametric Waveform

Once you have finished customizing a parametric waveform, you can obtain its array points. After selecting the chosen parametric waveform, tap the Wave button in the Shortcuts area and then the Get Array Points button. A new non-parametric waveform containing the array points is created and added to the waveform list, which you can later export and modify as you see fit.

Configurations

A configuration contains the data, in proprietary format, relative to the channel waveforms inserted into the sequencer and all the instrument and sequencer parameters.

Save As...

A configuration can be saved with the "Save As" button, which opens a dialog box as shown in the picture below. The configuration is saved in the configuration list, which can be accessed through the "Load From" dialog box.

On this page you can add a new configuration entry or overwrite an existing one. To create a new configuration entry, specify a name in the text box at the bottom of the page and then tap the "Add New" button.

Export Configuration

By tapping the Export Configuration button, a proprietary binary .zip file relative to the current configuration is exported. The exported file can be used to share configurations between different users or instruments.

Load From...

By pressing the "Load From" button in the "More" menu, a page opens that shows the list of all saved and imported configurations. By selecting an existing configuration, all the settings of that configuration are loaded into the instrument.

On the "Load From" page you can also manage the configuration list. It is possible to delete, import, or lock a configuration. When a configuration is locked it cannot be deleted or overwritten.

By pressing the Import Configuration button you can import a configuration file that was previously exported by a different instrument or by a different user. The imported configuration is inserted in the "Load From" list.

Remote Control

The Remote button in the Command Bar opens the page of the SCPI server. That page lists every command received by the SCPI server along with its replies. When the text of a command is displayed in green, the command is correct and has been accepted by the server. When the text of a command is displayed in red, the command is wrong and has not been accepted by the server.

The top of the page shows the Host Name and the IP Address of the instrument. The slider on the right side of the page enables or disables the SCPI server. It is enabled by default.

Remote Desktop Connection

Use the following credentials when connecting to the instrument through a remote desktop connection:

GPIB and USBTMC (with GP-IB / USB-TMC option only)

The VXI-11 server is always available to remotely control every parameter of the instrument. With the GP-IB / USB-TMC option, the Model 686 series also provides a GPIB electronic interface and a USBTMC port. Refer to the Programmer manual for a complete description of all instrument setting commands and data transfer commands.

GPIB control

Follow these steps to set up the instrument for remote communication over the GPIB (General Purpose Interface Bus) interface:

• Connect one side of a GPIB cable to the GPIB port of the Model 686 (on the rear panel), and your GPIB controller to the other side.
• In the Remote Control Panel window, verify that the GPIB Server Status is Enabled. If it is not, press the button to enable it.
• Set the GPIB address. A unique device address must be assigned to each device on the bus. The default setting for the GPIB configuration is Address [N] 20. To change the GPIB address, set it in the Address [N] parameter.

USBTMC control

The USBTMC protocol allows USB devices to communicate using IEEE 488 style messages. This lets you run SCPI commands over USB hardware.

• Connect an appropriate USB cable (A male to B male) between the USBTMC port of the 686 (on the rear panel) and your client PC.
• In the Remote Control Panel, verify that the USBTMC Server Status is Enabled. If it is not, press the button to enable it.
• If you are using NI-VISA software, launch the NI-MAX tool on the client PC. After a short time, a USBTMC device will be recognized.
• You can then send SCPI commands to the 686 resource using the NI VISA Test Panel.

Calibration & Diagnostic

The Calibration button in the More... menu opens the Calibration and Diagnostic page. The buttons on this page perform the following actions:

• Warm Up: Starts the instrument warm-up procedure, which takes 30 minutes. The elapsed time is shown. The procedure can be stopped with the Stop button at the bottom right of the Warm Up page.
• Calibration: Starts the self-calibration of the instrument. The procedure logs are displayed in a text box that can be saved at the end of the procedure for further analysis.
• Diagnostic: Starts the self-diagnostic of the instrument. The procedure logs are displayed in a text box that can be saved at the end of the procedure for further analysis.
• Load Factory: Loads the factory calibration parameters.

Multi-Instrument System

In a Multi-Instrument configuration, a Master device can control every triggering and timing setting in order to synchronize its operation with that of other Slave devices.

You can connect up to four Model 686 units to build a system with up to 16 synchronized analog channels and up to 128 digital channels.

Setting up the system

To set up a Multi-Instrument system, perform the following steps:

• Turn off the instruments.
• Select the instrument you want to use as Master. The other units are treated as Slaves.
• Using the 686-SYNC cable, connect the Master Sync Out connector to the Slave Sync In connector on the rear panel of the instruments. Then connect the Sync Out of that slave to the Sync In of the next slave device, and so on, up to the last slave device.

Once all the instruments are connected, turn them on and launch the Simple TrueArb application on every instrument.

Starting synchronized generation

The following steps describe how to set up a Multi-Instrument system and start the generation on two devices:

1. On the Master and Slave units, launch the Simple TrueArb application.
2. On the Master unit (the one with the Sync OUT port connected), a new Master Multi-Instrument toolbar appears.
3. On the Slave unit (the one with the Sync IN port connected), a new Slave Multi-Instrument toolbar appears.
4. Slide the Capture switch on in the Master Multi-Instrument toolbar.
5. The lock icon changes to show that a Slave device has been captured. The number of captured devices is now 1.
6. On the slave device, the lock icon also changes to show that the instrument has been captured by the Master.
7. Press Start on the Master device. Both the master and the slave instruments start synchronously. A lock symbol on the Start button of the captured instrument indicates that it is controlled by the master device.
8. To stop the generation, press the Stop button on the master device.
9. To unlink the instruments, slide the Release switch on the master device. The two devices can then be controlled independently through their respective interfaces.

Behavior of a Multi-Instrument system

As noted, the triggering and timing settings are managed by the instrument identified as Master. The table below summarizes how the Multi-Instrument system behaves for the settings that involve synchronization. Any parameters not shown can be set independently between the various instruments at the user's discretion.

Master Multi-Instrument bar

The Multi-Instrument toolbar appears on the Master device when it detects a connection with other 686 units through the 686-SYNC cable. The symbols are described below:

Slave Multi-Instrument toolbar

A new Multi-Instrument toolbar appears on the Slave device when it detects a connection with other 686 units through the 686-SYNC cable. The symbols are described below:

License

The License button in the More... menu opens the License page used to manage the license options.

The Memory Option and the Amplitude Option are predefined options. Otherwise, touching the Add New License button lets you enter a new license key to enable any of the following features:

Appendix A: Digital Option & Accessories

RIDER-MINI-SAS-HD

The 686-MINI-SAS-HD accessory is a mini-SAS HD cable 3.3 ft (1 m) long.

The end of the mini-SAS HD cable mates mechanically with standard mini-SAS HD connectors, but the electrical connection differs from the standard.

To connect the mini-SAS HD cable supplied with the digital option to your custom electronic board, you can use standard mini-SAS HD connectors (for example Amphenol 10112626-101LF, Amphenol 10112632-101LF, Amphenol 10120666-101LF, TE Connectivity 2198484-1, TE Connectivity 2227580-1), but you must use the electrical connection shown below.

AT-LVDS-SMA8

The AT-LVDS-SMA8 cable adapter converts from the mini-SAS HD connector on the rear panel of the instrument to 16 SMA connectors. This cable provides the signal integrity and flexibility needed to transmit the high-speed digital signals produced by the 686 generator.

The connections of the AT-LVDS-SMA8 cable adapter (mini-SAS HD to 16 SMA adapter cable, 8 differential output couples) are described below:

AT-DTTL8

The AT-DTTL8 is an 8-bit LVTTL adapter that converts the differential signals from the mini-SAS HD digital connector of the instrument to standard LVTTL single-ended signals. The RIDER-MINI-SAS-HD cable connects this adapter to the mini-SAS HD connector.

The probe lets you program the high-level voltage of the TTL signals by software, from 0.8 V to 3.8 V (into a high-impedance load). The AT-DTTL8 probe maximum bit rate is 125 Mbps at 0.8 V and 400 Mbps at 3.6 V.

Certifications

Berkeley Nucleonics Corporation certifies compliance with the following standards as of the time of publication. See the EC Declaration of Conformity document shipped with your product for current certifications.

EMC Compliance

EC Declaration of Conformity - EMC

The instrument meets the intent of EC Directive 2014/30/EU for Electromagnetic Compatibility. Compliance was demonstrated to the following specifications listed in the Official Journal of the European Communities:

EN 61326-1:2013, EN 61326-2-1:2013 EMC requirements for electrical equipment for measurement, control, and laboratory use.¹

Electromagnetic Emissions

Electromagnetic Immunity

Safety Compliance

EC Declaration of Conformity - Low Voltage

The instrument meets the intent of EC Directive 2014/35/EU for Product Safety. Compliance was demonstrated to the following specifications listed in the Official Journal of the European Communities:

The design of the instrument has been verified to conform to the following limits put forth by these standards:

• Mains Supply Connector: Overvoltage Category II. The instrument is intended to be supplied from the building wiring at utilization points (socket outlets and similar).
• Measuring Circuit Terminals: No rated measurement category. Terminals are not intended to be connected directly to the mains supply.
• Unit: Pollution Degree 2. Operating environment where normally only dry, non-conductive pollution occurs. Temporary conductivity caused by condensation should be expected.

Environmental Compliance

End-of-Life Handling

The instrument is marked to indicate that it complies with the applicable European Union requirements of Directives 2012/19/EU and 2013/56/EU on Waste Electrical and Electronic Equipment (WEEE) and Batteries.

The instrument is subject to disposal and recycling regulations that vary by country and region. Many countries prohibit the disposal of waste electronic equipment in standard waste receptacles.

Restriction of Hazardous Substances (RoHS)

This instrument and its accessories conform to the 2011/65/EU RoHS2 Directive.