Hello all,
There is an error which bothers me for long. It will be very kind of you if anyone can advise about it.
I used Labview 2017 SP version.I tried to run a delta-pulse measurement using Keithley 6221 with Keithley 2182A through TCP/IP. I find very often errors are generated by the VISA_Read in the error query vi. Sometimes I get green Error 1073676293 (The specified termination character was read) and sometimes it shows red Error 85 (occurred at Scan From String (arg 1)). See picture error1.
To examine the effect of VISA_Read, I made a simple test program consisted of reset and read function. And I get another error -1073807339 (Timeout expired before operation completed). See picture error4.
I was very confused with the read vi. So I decide to use test panel of Ni_Max. I write the query command ?IDN?\n in the test panel. I find enabling "Suppress End on Read" option will cause read operation timeout error (see picture test3.1). This problem can be solved after I disable it or enable the "Termination character" with line feed \n (see picture test1.1).
I am not sure either if it is a problem of Keithley device or my code or the communication set-up. I have checked the device can receive the signal for DC mode which does not involve reading of buffer. The device cannot be detected automatically by Ni_Max so I added manually using TCPIP socket with 1394 port. The GPIB cable will block the RS232 port which is needed for 6221 to communicate with 2182A, so I did not use it.
I spend many hours try to resolve it. It will be really helpful if someone can provide tips or hints to solve it.
Many thanks,
Thomas