Using Labview to access data from Modbus

[sjberg]

Hi All,

I posted a msg in another thread that I think was the wrong spot.

I am having problems with the modbus library and accessing data.

Please see:

http://forums.ni.com/ni/board/message?board.id=260&thread.id=234

Thanks

Steve

[dwisti]

Modbus has some terminology that goes back to its roots in PLC's.  You need to find out where the data is in the Modbus Server, Holding Registers or Input Registers.  Modbus also supports booleans which they call coils.  I suggest reading up a bit and becoming familiar with Modbus protocol.  Most info is available at www.modbus.org where you can download the modbus spec. Is this serial modbus or TCP? Also, you can use shared variables with a Modbus I/O Server instead of the library.  I'm not sure but I think you can create a Modbus I/O Server without having RT or DSC installed.


Message Edited by dwisti on 08-01-2008 04:01 PM