Thanks for this suggestion. Please have a look at the IO trace attached.
Lines 1-9 lines are the trace of using NI MAX.
Lines 10-14 using my vi sending just the command
Is there a difference between ASRL4::INSTR and COM4?
Oh Sorry the trace file cannot attach.
One difference is in the name. But I get only COM1 COM4 LPT in the options for the resource name. no ASRL.
I will try to paste the trace if needed.
The trace file is attached. First 2 lines are from executing command on NI-MAX and others are on running the attached vi.
Can somebody please tell what needs to be corrected?
Thanks Dennis. Before this, I had made a vi with only VISA Open, Write, Close. It didn't work. So tried to use config.
It is not responding to IDN query with VI but is respondin to IDN using MAX with return count 6.
In case it helps, I can't find visaconf.ini even after showing the hidden files and folders in the location C:\VXIPNP\WinNT\NIvisa. But COM4 is opening up on MAX as ASRL4 so that shouldn't be a problem. I can't think of anything.
Just one small comment.
The "Return count" out of VISA Write.vi has nothing to do with what your device is returning to a given command.
I used a Serial port monitor. Ran the command on MAX at 13:52, closed MAX at 13:53.
Ran the VI at 13:54:01.
RTS control signal is cleared as well as 'request cancels the specified requests' before closing the com port all at the same instant 13:54:01!
How do I prevent this clearing of buffers and cancelling of requests before vi close?
The port activity can be seen in the txt attached.