chroma DC power supply RS232 communciation( Read out problem for volatge and current )

[bstar]

Dear All .

I have chroma programmable DC power supply. Based on programming manual of the Instrument i develop communication using RS232. Based on the program i can set the voltage,current,over current protection,over voltage protection and make it ON/OFF out put of the supply perfectly.

But i have to  read measured values from the power supply output like current and voltage. The measured requests are voltage and current of the power supply output. my  problem is to read two of them at the same time. Currently  the read out is only either voaltge or current ( if the first request is VOLT? there is read out for voltage but no read out for current) and if the first request is CURR? the is read out for current but no for VOLT?. The status message is OK even if there is read out values .

Thank u in advance

[Dennis_Knutson]

Sorry, I forgot to come back to this from your other post.

I would recomend you actually use the termination character. To ignore and suppress it is extremely unusual. With it, your code becomes much simpler. Enable it at the VISA Configure Serial Port and for each of the VISA Reads, just set some arbitrarily high number of bytes to read. The VISA will automatically stop when the termination character is read and you will know you have read everything the instrument has sent. If you continue to have problems, try using the ERR? query to to what the instrument might be reporting as an error.

[bstar]

Dear Dennis

Thank you very much for your reaction.  I used all termination characters even before as u can see from my labview program. Even if there is no desplay on  the read buffer of the second measure request still the status messge is OK. Regarding to ERR? command ok i will check it and i will update you.

Thank u

bstar

[Dennis_Knutson · Accepted solution]

What I can see from your program is that you are not using the termination character for reads. For your writes, you are doing it the hard way with all those concantanate string functions. You can set the termination character for all writes with a single propert node - 'ASRL End Out'.

[bstar]

Dear Dennis

Thank u very much!

it works

Regards

bstar.