SDS1104X-E using PyVisa. Can I get more sigfigs/precision?  - Page 1
Forum section: electronics / testgear

author: SDMiller
author_rank: Newbie
timestamp: June 06, 2023, 09:10:22 pm
content: My goal is to make a string of automated measurements to calibrate the amplitude of a sine wave against the output of an RMS circuit. I can get it all talking and I get my measurements. On the scope I see the measurement as 20.0221kHz, but VISA reports 'C1:PAVA FREQ', '2.00E+05.'Question: Is there a way to get the full 4 digits of precision that I see on the scope out of pyVISA? I can deal with the format but with it rounding off like that it's making my test look better than it is.

author: alm
author_rank: Super Contributor
timestamp: June 06, 2023, 09:26:32 pm
content: This has nothing to do with PyVisa: PyVisa is just relaying what the scope sent back. You'll need to read the scope manual and see if the output format for measurements is configurable, or otherwise complain to Siglent.

author: SDMiller
author_rank: Newbie
timestamp: June 06, 2023, 11:13:19 pm
content: I've read the manual from Siglent. I don't see anything that looks like a measurement configuration but thought perhaps I was overlooking it. That was really my question, does anyone know if it can be done and if so how? It's not obvious from the manual but I'm not a VISA or Siglent expert.

author: abeyer
author_rank: Frequent Contributor
timestamp: June 07, 2023, 12:34:57 am
content: Tried this?:Code::FORM:DATA CUST,6

author: SDMiller
author_rank: Newbie
timestamp: June 07, 2023, 12:51:11 am
content: I hadn't, thanks for the suggestion. Tried it on my scope via Siglent's EasyScope and it accepts it as a command with no error but unfortunately the output is still rounded to the 3 digits. I also tried reading back the one of the custom params just in case it stored it there but no luck. Attached just in case I'm doing something wrong I can't see.>>>:FORM:DATA CUST,6>>>C1:PAVA? FreqC1:PAVA FREQ,2.16E+05Hz>>>C1:PAVA? CUST, 6>>>C1:PAVA? 6>>>C1:PAVA? CUST6

author: noisyee
author_rank: Contributor
timestamp: June 07, 2023, 06:51:59 am
content: What FW version do you use?I tried mine SDS1204X-E with latest V6.1.37R10, it works fine.Code:>>>FORM:DATA CUSTom,3>>>C1:PAVA? FREQC1:PAVA FREQ,1.00E+03Hz>>>FORM:DATA CUSTom,7>>>C1:PAVA? FREQC1:PAVA FREQ,1.000000E+03HzWait a second...Okay, I got it. It's a bugCode:>>>FORM:DATA CUST,3>>>C1:PAVA? FREQC1:PAVA FREQ,1.000000E+03Hz>>>FORM:DATA CUST,5>>>C1:PAVA? FREQC1:PAVA FREQ,1.000000E+03HzThe short form of CUSTom doesn't workCode:>>>FORM:DATA CUSTom,6>>>:FORMat:DATA?FORM:DATA CUSTOM,6>>>FORM:DATA CUST,3>>>:FORMat:DATA?FORM:DATA CUSTOM,6

author: SDMiller
author_rank: Newbie
timestamp: June 07, 2023, 03:40:26 pm
content: Thanks a ton for sticking with this. It was a combination of the CUSTom and that I was running older FW. Upgraded to 1.37R10 and now I'm seeing exactly what you're seeing. That's what I needed!>>>:FORMat:DATA?FORM:DATA CUSTOM,7>>>C1:PAVA? FREQC1:PAVA FREQ,3.003000E+04Hz>>>FORM:DATA CUSTom,6>>>:FORMat:DATA?FORM:DATA CUSTOM,6>>>C1:PAVA? FREQC1:PAVA FREQ,3.00300E+04HzSimon

author: 807
author_rank: Frequent Contributor
timestamp: June 08, 2023, 02:13:52 pm
content: Quote from: SDMiller on June 06, 2023, 09:10:22 pmDoesn't 2.00E+05 represent 200kHz, or am I having a brain fart in my old age?