How do I communicate with ComputerBoards Inc CB-7520 & CB-7018 modules?

[EddyMerckx]

Here is my setup:
ComputerBoards Inc CB-7520 (RS-485 TO RS-232) and CB-7018 (8 INPUT THERMOCOUPLE) modules, LabVIEW 6.1 running on a PC (Windows2000).

Here is my problem:
ComputerBoards Inc gives a set of serial interface commands that can be issued over the RS-232 interface to read and configure the modules. If I use HyperTerminal (9600 Baud, 8 Bit, No parity, 1 stop, no flow control) the commands work fine and I an take temperature data manually. When I try to do this with LabVIEW (using the same port configuration paranmeters) and automate the process, I get no response from the modules. Does LabVIEW do something strange to COM ports so that they can't be read? Or does ComputerBoa
rds Inc. use some kind of "special" port configuration just to make peoples lives more difficult?

I know CB.com sells software for interfacing these modules with LabVIEW, but I think that if NI says I can command the serial port, and CB says I can use serial commands to take data, I should be able to do both together.

I have attached the VI I am trying to use. It is very simple.

DAN ALLIS
ASSOC. MECH. ENG.
ANALOGIC CORP.

[AaronK]

Hi Dan,
I cannot speak for ComputerBoards, but I can tell you that LabVIEW does not do "something strange" to the COM ports. I would recommend trying one of the example Vi's that are included with LabVIEW. Start with a loopback test where you connect the Tx and Rx lines together. If this works, proceed on to communication with your instrument. If you are still having trouble, make sure that you are sending the proper end of line character. This can be determined by looking in the manual.

Hope this helps Dan.

Best Regards,
Aaron K.
Application Engineer

National Instruments