Im opening my com port trough MAX and the VISA test panel and I have to change the attribute "Flow Control Settings / Data terminal ready DTR" from Asserted to Unasserted in order to be able to write the data I want to write to the RS232 device using the input output window. While doing that I have NI I/O scope running and can see that the data I write is in the buffer and my device reacts as I wish.
I now wrote an VI that does exactly the same, I set the COM port and change the DTR setting through the property node. I can see the change in the NI I/O scope and then I write the same data again into the device again seeing the buffer in the NI I/O scope. But the data is not written correctly into the device.
The only difference I can see in the NI I/O scope is that in the first case the COM port ist being addressed like "
28. viSetAttribute (ASRL7::INSTR (0x0375A008), ASRL_DTR_STATE, 0)
Prozess-ID: 0x00000B90 Thread-ID: 0x0000129C
Startzeitpunkt: 16:10:51.259 Aufrufdauer 00:00:00.000
Status: 0 (VI_SUCCESS)
"
and in my vi it shows up "
780. VISA Set Attribute ("COM7", 0x3FFF00B4, 0)
Prozess-ID: 0x00000FA0 Thread-ID: 0x00001388
Startzeitpunkt: 17:04:49.730 Aufrufdauer 00:00:00.000
Status: 0 (VI_SUCCESS)
"
Can this whole problem be in the way the system addresses the functions in each case?
MEnaing once using viSetAtribute and the other time VISA set attribute and then ASRL7::INST and then COM7?
