modbus serial

[Khalid]

Modbus Data Unit Out is the result. You will expand the Data array to see the data. But, in your case you aren't getting any data apparently (and so you're seeing the default values).

If you look at the error-out, you will see the query is timing out. So, you may want to verify your COM port settings (baud, parity, etc.), cabling, etc. Did you mention the pump's software works? If that's the case, you will want to use the same exact settings.

Hope this helps.

Regards,

-Khalid

Message Edited by Khalid on 10-07-2006 11:50 PM

[azaibi]

Khalid,

Thanks a lot for your help. I tried preceding the modbus master query with a serial init sub-VI, with the correct settings, but still no result. Any clues?

[Khalid]

On the Init subVI, have you saved the control-values as default? If not, the VI will revert to whatever values it has as default (which may be different). Alternativley, you can wire-in constant values on the diagram into this Init VI.

The other thing I would try is, run your software that came with the device (which I am assuming is working), and compare its Modbus message with the one that the LabVIEW is writing out. You can do this by using any Serial port monitor. I personally like and use Portmon:

http://www.sysinternals.com/utilities/portmon.html

Hope this helps.

-Khalid

[Khalid]

Hi Adam,

Was just wondering if you got this to work. 

-Khalid