Instrument Control (GPIB, Serial, VISA, IVI)
Error Reading from HP 66xx PSU
Solved!
/* New user warning */
I have been learning (slowly) to get a set of external instuments connected to LabView. For the most part, I have been succesful reading and writing commands and data from basic instruments. There is a problem that I cannot figure out with both of my Agilent 6653A power supplies.
I can get the supplies to turn output on/off as well as adjust volts/amps. The problem is trying to read measured volts and amps back. The VI freezes and offers an error message that I do not understand. Here are some screen shots, if it is helpful to upload the VI's, of course I can do that.
This is a test VI that only function is to have basic control of the power supply and a Keithley DMM to do a comparison read. Both work just fine until I add the READ MEAS vi on the power supply section of the block diagram. It seemed simple, pass the VISA and ERROR through and it should spit out the voltage and current as a DBL.
I manually tested the commands and the returned data looked ok.
FIRST ERROR........
SECOND ERROR......This one is related the Keithley DMM
Not sure where to look for an answer. Hoping there is a simple answer.
Thanks in advance to anyone willing to take the time to help.
Simple enough, so I tried just deleting the code related to the DMM. Thank you for the time Dennis.
I am now left with this, which works without the READ MEAS.vi, but generates the VISA error with it.
It seems easy enough, but clearly something is not right. I have read through the Agilent manual, but can't connect the dots from that information either.
The ethernet interface is a Tektronix AD007. Seems to be ok for just about everything, this is the first real issue that I have run into.
Not sure if it helps, but I have manually issued the commands with no trouble. The READ MEAS.vi seems to get stuck right at the beginning [VISA enable event]. I have also been running the READ MEAS.vi all by itself in an attempt to isolate it. Do you suppose the VISA event type needs to change (currently its set to SERVICE REQUEST).
I copied the vi and removed the 'VISA Enable Event' and it seems to be working just fine now.
This is part of the standard driver package for these power supplies. What do you suppose the VISA Enable Event was/is intended to accomplish? Someone with vastly more experience than me put it in there, so I am wondering if I 'fixed' one thing and breaking another thing in the process.
