How to connect to an old giga-tronics 910 with gpib 488.1 or 488-1978

[Dennis_Knutson]

MAX and the GPIB functions (as opposed to VISA) should work the same. You might try experimenting with the mode setting of the GPIB Write function and see if that makes a difference. You could also turn on NI Spy during the communication with MAX to see if there's any difference.

[bolometer]

Yes, I did try NI spy and the lines I posted on previous message were recored by NIspy.
First a few lines are very simple commands that MAX sent and received.
Then when use labview write there are severl lines and espcially the functions are ibrda instead of ibrd, and ibwrta instead of ibwrt.
I tried eliminate all parameters that hook to GPIB write, except the address string, but from the NI spy they are the same.

There is a GPIB misc in labview, trid a few commands, still quit different from using MAX.

I am still not sure if using GPIB can make a vi the same as the communication tool in MAX. Otherwise there could be a direct tool in the labview.

[Dennis_Knutson]

Sorry. I missed your note that the NI-Spy was done with both MAX and GPIB calls. The difference between ibwrt and ibwrta is that ibwrt is done asynchronously. Normally, you can right click on the GPIB function and choose which way you want to do it. The big difference I see is that you have two different device descriptors. The ones you did in MAX are to UD0 and the other's are to UD2. UD0 is normally the address of the controller. Can you confirm the GPIB addresses of both the controller and instrument? When you scan for instruments, what does MAX return? When you communicate to the instrument in MAX, how are you doing it?

[bolometer]

Problem solved!
It was my mistake that used FA 12.3e+3 instead of FA 12.3E+3. Need use capital E.
Both "Do I/O synchronously" or asynchronously works.
In summary, opened the case and switched to the GIGA syntax, and then be careful use the right capital words.

Really appreciate you help!

J