Problem qith RS232 serial communication

[Carras]

Hello!
I want to contro a Digital MultiMeter with Labview 5.1. The interfece that I must use is RS232C. A byte has to be sent to the DMM and then it answers with 14 bytes. The data protocol is 600 7n2, and helped with an oscilloscope, I know that the DMM recibes the byte and sends the answer, but PC doesn't recibe it.
The DMM has a program that communicates propperly with him. I have seen that when the PC communicates with the DMM, the DC level in the Rx pin increases +5V DC, which doesn't occur when the DMM's program is used. I don´t know what to do, if there is a program that can communicate with th DMM, Labview will be able to do ot too, won´t it?

Thanks!

[Diego_M]

Hi carras,

you can do a communication with Labview 5.1 using the serial functions that you can find in your labview license.

1. Firstly, you need to have the best version on NI-Serial (driver to communicate with your instrument using a serial port) to work with Labview 5.1 and your operating system. You´d be able to find it out on the following web page: http://digital.ni.com/softlib.nsf/MainPage?ReadForm&node=132010_US

2. Typically, you have to work with the Read and Write vi´s to communicate with your instrument.

3. On the labview´s Help you´ll be able to find some example to communicate on serial port with your instruments.
Moreover, you can download an instrument driver for your instrument on the web page: http://www.ni.com/devzone/idnet/. An instrument driver is a set of software routines that control a programmable instrument in order to reduce and simplify the program and not to have to learn the programming protocol for your instrument.

One tip would be to upgrade your version of Labview due to you can have some problem to find the instrument driver or other information that you can need in the future, for example, support of application engineer of National Instruments and so on...

Regards

Diego M.

[AnalogKid2DigitalMan]

Who is the manufacturer of the DMM and what model is it? Perchance Radio Shack?

[Carras]

Hi!

Thanks for your interes. Manofacture is VELLEMAN (www.velleman.be), and the model is DVM345DI. I've tried to find drivers or update, but I found nothing. Could you help me with this additional information? I really don´t know what to do.

Thank you!!!

Carras