(1) I saw a similar posting before, but no solution. Perhaps I can explain better what is happening. I'm running Windows 2000, opening LabVIEW 6.0.2 and trying to do simple GPIB communication with an Agilent E4419B EPM Series Power Meter--GPIB Clear, Initialization, Write (a simple command, i.e., *IDN?), then Read. I get error number 3 (out of zone, or GPIB not addressed correctly) at the GPIB Write. Then I open MAX, find my instrument under "Devices & Interfaces" and right click on it to choose "Communicate with Instrument". The NI-488.2 Communicator comes up where I can type in a string and query, write, or read. Here, I can either actually send a command (i.e., *IDN?), or just click exit--it doesn't really matte
r if I actually use the NI-488.2 Communicator or not. All that matters is that I open it up and exit. After exiting that, I can then go back to LabVIEW, run the exact same VI that caused error 3 before, and execute it without any errors or warnings. What is MAX doing that I'm not? From then on, LabVIEW communicates fine. I can even power off the instrument and turn it back on--communication is still fine. However, once I exit completely out of LabVIEW, I have the same problem all over again. Help!
(2) Sending the MEAS? command works (of course, after I open up MAX first--see above problem) in LabVIEW, but takes what I think is unusually long. The VI is not in a loop, and only does those things described above (GPIB Clear, Initialization, Write, Read).. it's very simple. But the MEAS? command takes approximately 5 seconds to produce a result. Is this normal??