John Cook

After a lot of reading of the manual the solution is to turn on the measurement state, like this:

:MEASUrement:MEASx:SOUrce CHchannel;:MEASUREMENT:MEASx:STATE ON

Notice you need the semi-colon and leading colon of the second command that turns on the state of measurement, so the measurement actually happens.

What I am seeing is that the scope sends just the value the first time, or sometimes the second time you take a measurement, and every time after it sends the full string.  I have written some Python to parse the value from the string and to detect when it is sending just the value or the string so I am good to go now, but this is an annoying "feature".
 

I'm having troubles getting a useful response from a measurement command.  The result is zero all the time, for every type of measurement.  Here's the setup:

Inject a 10kHz 4Vp-p sine wave from a signal generator into a TEK MSO5204B on channel 4.  Use SCPI commands to turn on CH4 and put the scope in "RUN" mode.

Send these SCPI commands:
MEASUrement:MEAS1:SOUrce CH4
MEASUrement:MEAS1:TYPE FREQUENCY;ACQUIRE:STATE ON
MEASUrement:MEAS1:VALue?

The scope's measurement setup page will show Frequency as measurement number 1 on CH4
The query returns the following result:

:MEASUREMENT:MEAS1:VALUE 0.00000000000 FREQ

I can parse out the value easily enough but the value should be 10 kHz, not zero.

Any suggestions?
Thanks.

Hello,
My co-worker and I are using TEK MSO5000 and TEK MSO56 type scopes and trying to automate taking measurements.

We're doing pretty good, got the scope to respond to commands to setup measurement and also to give us a response.

Commands to setup a measurement look like this:

MEASUrement:MEAS3:TYPE AMPLITUDE; ACQUIRE:STATE ON

And to get a response, we'd send this:

MEASUrement:MEAS3:VALue?

Now the not-so-nice part.  Sometimes the response is just the value:  "2.453" and sometimes the result is a string that echos the command and also the response:  ":MEASUREMENT:IMMED:VALUE 2.453"

What I'd like is just the value, so I can use a python cast and make it a nice floating point value and I'm good to go.  The manual says that the response is the second one, with all that text.

My co-worker and I are using two different scopes, in two different labs and found that sometimes we get just the value, and sometimes the command and value, and we can't figure out why its one sometimes, and sometimes the other.  We think its a bug in the 'scope firmware.  Anybody got some feedback?  Thanks.