ASCII protocol & Labview 7.1 + PCI-2323/8

[scott-e]

Greetings, I'm trying to do a simple command and response with labview 7.1 adn a varian multigauge that accepts ASCII Protocol. For now, I would be happy just to get a response back from the instrument. I'm not sure that I'm setting the program up correctly ( see attachment). I'm not getting a response to dat, so I was hoping that someone could give me some feedback.


Here is the data on the multigauge comms. Varian Multi-Gauge Controller accepts RS-232 communication in ASCII protocol:
Baud is selectable (9600 is selected)
Parity is selectable (none is selected)
unit address is selectable ( aa is selected)

All LOWER-CASE characters are placeholders and the command format is:
# {address} {command} {data} {carriage return}
The response is:
{ data} {carriage return}

Example: sending command to read software version is: #aa05t

aa = 2 character hex bus address.
05 = 2 character hex byte value.
t = message terminator character (#13, charage return character).

response is: hhhht, where software version is hh.hh
hh = 2 character hex value
t = message terminator

I also included a manual of the multigauge + generic VISA. Any help would be appreciated.
Scott

[Dennis_Knutson]

When you post something like this, you should enter data into the controls and then go to Operate>Make Current Values Default. As it is, no one knows what command you're sending and whether it has the right syntax. You should also include VISA Configure Serial Port to set baud rate, etc. Make sure these settings match what the instrument is set to. Page L-15 of the manual includes some advice that I always recomend. That's to use the built-in windows terminal emulation program Hyperterminal, before doing any custom programming. Do this first and make sure your cable and com port settings are correct. When you do get that working and get back to LabVIEW, wire the error out of VISA Write to the error in of VISA read and wire your error cluster indicator to the error out of VISA Read. Without doing that, you'll never know if VISA Read is giving you an error.