RoadTest: RoadTest Keysight BenchVue
Evaluation Type: Independent Products
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: Scripting.
What were the biggest problems encountered?:
BenchVue is a free program from Keysight that allows you to control test equipment from a PC using a graphical interface. The program is comprised of apps for each instrument; for example a DMM app and an oscilloscope app. Each app has a pro version which costs extra and enables extra features. There is an additional app called Test Flow used to create automated test sequences.
As a road tester I was given the following:
BenchVue DMM Pro – MSRP $206.00
According to Keysight’s website, this Pro version (model # BV0001A) provides histograms, digitizer capability (on select DMMs) and unrestricted data logging (vs one hour on the free version) with limit checking and alerts.
BenchVue Oscilloscope Pro – MSRP $400.00
According to Keysight’s website, this Pro version (model # BV0004A) provides unrestricted measurement data logging (vs one hour on the free version) with limit checking and alerts.
BenchVue Test Flow – MSRP $303.00
As mentioned earlier, this is the app used to generate automated test sequences.
For the review, I plan to use a DOSX2000 Scope, 34465A DMM and an E3646A Power Supply. Supposedly, Test Flow allows the user to interact with instruments not supported by BenchVue using SCPI commands, I will test this with a Tek scope.
Installation and Initial Impression
Installing BenchVue is pretty straight forward: download and install. I opted to install the BenchLink Waveform Builder although I don’t think I will review it this time around. With the initial installation, apps for the DMM, Function Generator, Oscilloscope, Power Supply and a demo of Test Flow are automatically installed. It seems you can get a free 30 day trial for any of the pro apps.
The program has multiple tabs; they are as follows: Bench, where your virtual bench is displayed. Apps, where you install and manage apps. Data Manager, where you can see data logs, (it seems that you can filter the saved logs by date range or by the instrument used for logging). Library, which contains examples and links to YouTube videos, (it seems all the examples are for Test Flow).
Adding instruments is done through Keysight’s Connection Manger. The USB devices are automatically detected, and once the correct information for the COM port was entered the PSU which only has a serial connection was automatically detected. Once added, images of the available instruments are displayed at the bottom of the program.
Clicking on any of the images adds the instrument to the virtual bench. The layout of the bench seems limited to four preconfigured arrangements where all instruments occupy equal amounts of space on the screen, and so with all three instruments open, the scope widow is very crowded. You can open each instrument in an independent window, however, this is not as elegant and makes it harder to access the “start all” and “stop all” buttons.
To test the program I connected the scope to the built in Wave Gen and connected the PSU to the DMM one output for voltage the other current (Using four 100 Ohm resistors in parallel).
I’ll first review the program in general then I will get into the details for each of the inurement apps as well as Test Flow and the mobile app.
I’m not a big fan of USB scopes, I would much rather use buttons and dials than click the mouse, so why turn my old school scope into a USB scope? There are a few potential benefits: 1) a centralized panel to view multiple instruments, 2) data logging (which seems to me to be a central focus of the program), 3) remote monitoring using the mobile app, 4) automated testing using Test Flow, and 5) when you need to use the computer for other test elements (for example, sending commands to a DUT to trigger certain states).
Overall the user interface is pretty intuitive: select the instruments you want to use and add them to your virtual bench. Then once they are added you can control and configure them in a pretty straightforward manner. One thing I noticed is that the instruments can either be controlled manually or using the virtual bench, but not using both at the same time.
Each inurement has a data logger window where you can configure the settings for data logging and initiating log can be done for all active instruments or each instrument individually. Once you click “stop” the log is automatically saved. When logging from multiple instruments, each instrument has an independent log. Viewing the logs is done using the data manager. Depending on the instrument, there are different formats for viewing the data, and but each data log stores the instrument configuration and data. The fact that logs are saved independently, even when using the “start all” button, means it can be tough to correlate logs from a single experiment when viewing past logs you, if you didn’t rename the logs.
Some instruments have a limit testing feature which allows you to set an upper and lower limit and can either beep, send an email, or execute a batch file when the limit is reached.
Logs can be exported to CSV, Excel, Matlab and Word, (exporting to word creates a document with the inurement settings and a screenshot of what is being displayed in the log viewer - the other format are standard). The only option I’ve found to export multiple logs was from the bench tab, which means that the only way to export multiple logs is if those were the most recent logs created.
The PSU app is probably the simplest and most direct; you can set the voltage and current for each of the outputs and view the measured values. The data logger page shows a plot of the measured values, but I can was only able to log a single value, either current or voltage, from a single output. While logging is active the instrument settings cannot be modified.
Let’s start with what I find inefficient: the only way I found to view live values from the DMM was during logging, which can be inconvenient if you want to just monitor and control your bench without creating logs. Besides for the one downside the app is pretty good at allowing you to configure and measure almost anything that you would on the DMM.
The pro version adds the Digitizer feature which allows you to set up triggering and fixed-time sampling, which effectively turns the DMM into a slow scope. There is a digitizing option that can be purchased for the DMM. I did not purchase the option, but can still use the feature in BenchVue (I am missing the option to use an internal trigger but I am not sure if this is related). A useful feature when using the digitizer mode is the ability to drag cursors and set annotations on the plot of the measurement. In the images below; you can see screenshots of the digitize mode used to measure the current of an RF module that sends a packet approximately every 10 seconds.
The most advanced instrument app (of those I am reviewing) is without a doubt the Oscilloscope app, it pretty much transfers the scope (albeit with less functionality) to your computer screen including the WaveGen. The instrument settings window allows you to scale the scope, configure the trigger and select measurements. Hovering the mouse pointer over the waveform will give you the value at that point but I could not find an option to add cursors. Trigger options were limited to edge, pulse width and pattern and anything other than the edge triggers needs to be configured on the physical scope. Measurements are also limited to frequency, rise time, fall time, min, max and peak to peak but other measurements can be set on the physical scope.
The app also has a screen image tab where you can capture and annotate a screenshot from the scope. There is also a trace data tab where you can get all the data points from the trace (I am not sure what amount of data points the main window has). While the trace data tab does allow you to transfer the math, data as well it has to be configured on the scope. For some reason when transferring the waveforms and a math trace the amount of data points that are transferred drops from 500,000 to 62,500.
The last tab is the Measurement Datalog which logs and plots the active measurements (some that can only be selected on the physical scope). This is the logging that occurs when clicking the “start all” button on the main BenchVue toolbar.
I often use the serial decode features on the scope but I couldn’t find a way to do this using BenchVue. Being able to do this would be ideal since one of the main functions I see myself using BenchVue for is to debug serial communication using my computer.
Test flow is essentially a GUI for programming test sequences: you write the sequence by dragging blocks into the “Flow”. There are two types of blocks: generic blocks, (like loops, delays and variables) and instrument-specific blocks for the instruments currently active in your virtual bench. Blocks are selected from the test flow window and the instrument-specific blocks can also be selected from the instrument app by dragging highlighted orange boxes. The process of finding the correct boxes and then dragging boxes into the sequence takes some getting used to but once you get more familiar with the software setting up test sequences is really quick. There are some nice features that make setting up a flow quick; for example, when adding PSU output, there is a “sweep” option as opposed to configuring a loop.
You can either single step through the sequence or run it continuously. While the sequence is running the current stage is highlighted and when in a loop, the current loop count is displayed. To the right of the sequence, a chart of the values is displayed along with a plot and both are updated live. The plot can either be set as either a line chart or an X-Y plot.
There are advanced blocks which are “command expert” allowing you to execute a command expert sequence. (Side note, if you write scripts for test sequences check out Keysight’s Command Expert-it works with non Keysight instruments as well). SCPI which allows you to send SCPI commands to instruments, this allows you to integrate instruments that are not supported by BenchVue. For example I was able to use a Tektronix scope in Test Flow this is a bit more cumbersome, but can be useful if you have many supported Keysight instruments. (If you only have non supported instruments good old scripting is probably better.) Lastly, you can run external programs which can be used to integrate scripting (for example to trigger events in your test setup) although you can’t get a return value.
A note on the mobile app
You can monitor and control your virtual bench on your smartphone or tablet via the BenchVue mobile app connected to the same network. I personally don’t have much use for it so it’s tough for me to review but if you need to monitor an experiment remotely (on the same network) you should look into this.
Test Flow aside, BenchVue is a unique piece of software allowing the bench to be controlled with a simple user interface, I personally prefer to use my physical scope because of the fact that I like using buttons and knobs, and many of the scopes more advance features are not available in the software forcing you to use both BenchVue and the physical scope. However, I do like the PSU app and the digitizing feature on the DMM (but those features would not be enough for me to purchase the pro versions). That being said, definitely download the software (the basic version is free) and try it for yourself. Like I said, I really like the user interface and maybe there are benefits for your application, especially if you do a lot of data logging.
Once you get the hang of it test flow is really a great piece of software and if you run any test sequences (even not automated) you should give it a try. You can easily set up an automated test sequence and see live feedback while your test runs.
I would like to thank Element 14 and Keysight for the opportunity to review this product.
I also would like to mention that this is my first time reviewing a product and any constructive criticism would be appreciated.