Hi there,
I have encountered a problem with different drivers if these make use of VISA READS. In case a Visa Read follows a Visa Write, in a first run the read buffer never outputs the right data but a “DCL” (Device Clear?) or line feed or the result of another previous Write command, but the next times the same VI runs the Visa Read outputs the expected data, although maybe not the complete string. There is not timeout error. It seems like the VISA Reads have a triggering problem. I am using NI-VISA 14.0 in labview 2014 to control my keithley 6221 instrument as a TCPIP socket. The MAX software successfully opens the instrument and a VISA Test Panel can be used. Here, the parameters are
Hostname: 192.168.001.003
Address: 192.168.1.3
Port 1394
No packet delay
Send End on Writes
Suppress End on Reads
Enable Termination Character (LF)
Advanced settings:
Acquire Exclusive Lock
Events Enable
Trigger Protocol Default
With this Test Panel I check the instrument “ID query?” that gives “No error”, however the “Read STB” command does not work and other attempts to change settings or “Assert trigger” give error VI_ERROR_INV_SETUP
What parameters could avoid the triggering/reading problem? Can anyone advice on this? How to fix it?
Jose M. Colino
