Is there any way to concatenate SCPI commands in test flow? when i try i get "Cannot concatenate two SCPI commands in one step". However, i have equipment that needs *WAI command concatenated to measurement queries to hold the GPIB bus while the measurements are made!
Well, we've tried this here at Keysight and it doesn't work. A way to get around this is to use a Command Expert block and send the SCPI commands through Command Expert. Command Expert is free, and you can get it from www.keysight.com/find/commandexpert
@solid, You can access the Command Expert block from the Advanced menu where you found the SCPI block. Just develop your SCPI sequence in Command Expert and load the file to the block. Test Flow will execute it behind the scenes. As mentioned you can download CE from the website above or from the Apps Tab in BenchVue
Yes, thought of that but unfortunately command expert block is missing from benchvue even though the app is installed. I think thats a separate problem. Also, Command expert is not connecting to the server! Any ideas on how to fix these issues? It's a fresh install just today.
The Command Expert server is down today, for some unknown reason. Hopefully it will be back up today, or tonight.
Hmm, did you install BenchVue or Command Expert first?
Installed benchvue2017 then installed the command expert app through benchvue app tab.
here's my advanced blocks
and here's my installed apps
Can you click the "Report an Issue" under the conversation bubble in BenchVue? Add my email (connectivity.support@keysight.com) to the email and send it in. Then I can diagnose why Command Expert isn't detected.
done
#Solid, do you have a license for any of the apps or a trial enabled ? The command expert block in Test Flow won't show up unless you have an app license or a trial enabled.
no licence or trial. Didn't know I needed one. I just downloaded benchvue2017 installed then installed command expert app. wasn't prompted for trial activation or licence. Command expert shows up as a free app in bencevue2017.
@solid, Command Expert is free. You can download it and use it without any licenses. If you want to use it with Test Flow and instrument applications to automate any controls and measurements, then a license is needed. You can initiate a trial directly from the App Tab, by clicking on the application of your choice and choosing Start Trial from the details page.
Hi Sid,
There is no option for trial or licence in command expert app. see screen shot. note this is 2017 version.
Hi @Solid,
Sorry about the confusion - I re-read my comment above and realized it wasn't very clear. Command Expert itself doesn't need a license. The model for BenchVue 2017 is as follows : Each instrument application ( ex. BenchVue Oscilloscope, BenchVue Digital Multimeter etc available in the App Tab ) requires a license or trial in order to use. Once a trial/license for these instrument applications has been activated, Test Flow can be used with the application ( i.e. you can now drag and drop the orange boxes from the application into Test Flow to automate functionality ). This also adds a command expert block in the advanced menu.
The only thing is Test Flow you can do without an instrument application license is use the SCPI block. If all you want to do is use SCPI directly and need a command expert block, the best option would be to enable any instrument application license/trial. This will open up use of the CE block for 30 days.
Let me know if this isn't clear.
Sid
Thanks Sid. Its clear now. I need to install and activate an instrument application to open up command expert in test flow. Getting back to my original issue... I've tried concatenated commands in command expert and I can't do them there either! Here's why concatenated commands are necessary. I have an AC source, I send a MEAS:VOLT:AC? command but get a null response. If I send MEAS:VOLT:AC?;*WAI I get the correct response. The reason being the *WAI command holds the gpib bus until the AC source can complete the measurement. The *WAI must be concatenated to the query or it will not work. the commands cannot be separated. Why has concatenated commands been disabled in benchvue? It makes using it (at least in its SCPI embodiment) much more difficult!
Anyway, thanks for all your help. I've sent feedback and suggestions through benchvue.
Regards,
Brian
Hi Brian (solid) -
Actually, the SCPI block DOES allow concatenated SCPI commands. Don't use the "Validate" button which will give you the error message you saw (and which is a bug). Also, turn off the "Clear Errors" checkbox inside the gear icon for that block to avoid having it send "syst:err?" queries until it reads 0,"No error". You can concatenate all you want if you just run the block instead of validating it. That said, I *have* seen some oddities when using the IEEE-488 commands such as *IDN?. Not sure if *WAI is OK, but please try it and let me know.
Some apps do not like SCPI being sent to the instrument if the app is running. So you may have to close the app to use the SCPI block. This is because the app is constantly reading status from the instrument and may not interleave commands from Test Flow properly. This is a situation we need to fix.
You also asked for a pause button. The blue button between the start and stop buttons is a single step button. If you need to pause execution during Test Flow, use the Prompt block, which will pause execution waiting for you to click Continue.
Brian Wood
BenchVue Support
Thanks Wodz. Concatenation works perfectly (*WAI function included). Regarding the pause button. Generally my data acquisition sequence is running in a loop. adding a prompt would require user input on every loop cycle which is impractical. If the step/pause button was enabled when the sequence is running it would allow me to pause the program if a problem occurs with my DUT and then restart on the same dataset once I have rectified the problem. would make the program much more usable. As it is every test must run smoothly (which usually doesn't happen) to get one good dataset. Otherwise I have to combine multiple datasets.
Thanks again for your help.
Although a little klunky, you could put a prompt inside an if-then-else statement, and test for a bad condition. If the condition becomes true, you could then prompt the user to hit the big red kill switch to stop letting the smoke out. You could also just use the if-then-stop statement to stop automatically on a fault condition. There's also the Pass/Fail Test block that could be used for this. I know that means littering your sequence with lots of otherwise unneeded stuff, so I get that you'd prefer a pause button. I've been lobbying for an "event" handler that could execute asynchronously when some event occurred, like the user hitting a button, or an alarm signal being received. It's basically an interrupt capability that's needed. Someday...
Brian
Thats fine brian. Just giving feedback.
Can you just separate them with a semicolon?
Can you provide an example of the commands that you want to send together?