11-30-2007 12:28 AM
10-07-2009 04:30 PM
hi there,
looking through your NI logs, it appears that you have succesfully established serial communication (a long time ago) with your Varian multigauge controller. I have set the dip switch as specified for straight connection, but am not able to get pressure readings from the controller. two things are possibel wrong.
1. The RS-232 card on the controller is not working. You cannot help me here.
2. I am typing the wrong command. Is it possible for you to share the command you write to the controller to read the pressure?
Ujjwal
10-09-2009 11:09 AM
I don't have much experience with the Varian controller, but to help with sanity, you can verufy the serial port is working by performing a loopback test. Here are some helpful articles and examples:
How to Do a Serial Loopback Test
LabVIEW Loopback Test for Serial Port
Sweet Serial Loopback/Timeout Demo
Goodluck!
10-09-2009 11:16 AM
Peter,
The problem is not with my COM port or the RS-232 cable. I did perform the loop back test to check this already. So there are a few possibilites left.
1. The RS-232 card (hardware) on the unit does not work properly. Any test you could recommend here?
2. The command I am sending to the unit has a typo error - but Varian was able to talk to their controller using the same command.
3. probably, the firmware loaded onto the unit is not configured to read ascii commands.
I am trying to work on the 3rd issue.
Thanks
Ujjwal
10-12-2009 10:02 AM
Like you have said, I would see the problem could lie in the format/content of the message. Maybe termination charater?
Did you confirm with Vatrian that your command is correct? If you post the manual for the device, and post exactly what you are sending, we can help verify your string.
If this is correct, it may be a hardware error in the Varian device. As far as seperating the 232 interface from the actualcontroller in the device, I would not have any suggestions. If you had another similar instrument around, it could help to identify if it is bad hardware or a bad command.