Monitoring and controlling the Tag values of Logix 5000 using Labview while using RSLogix 5000 to program the PLC

[msu]

Hi

  I want to know how to change the input bits or tags of a PLC which is programmed using RSlogix 5000. But I need to use Labview to monitor the input bits ( like in Digitial Input bits) and then be able to change the BITS while the PLC runs and the PLC should be able to detect the change in input bits and act accordingly. The programming is done using ladder logic and its done in RSLogix 5000 and dumped into PLC using RSLogix.

Thanks in advance

[Justin D]

msu,

What model PLC is this?  How does it communicate (serial, ethernet, etc...)?  Does it have an OPC server?  We need a little bit more information before we can suggest anything specific for you.

Justin D.

[msu]

The PLC is AB LOGIX5000 We connect to the computer using ethernet cable. I came to know that we can use OPC server to communicate with the PLC  I/O points but I have pbm with how to use the OPC server. Can anybody suggest how to configure the OPC server with LabView and can anybody send a Example Vi on how to access the I/O points? Thanx

[Justin D]

msu,

Once you have the OPC server up and running the best way to communicate with is is through the Datalogging and Supervisory Control module for LabVIEW.  The DSC module allows you to bind shared variables to items on your OPC server.  Then you could just read from or write to these shared variables to access the data on this OPC server.  If you don't want to get this module you could also just use datasocket to read/write from an OPC server.  The URL you would use in data socket would look something like "opc://localhost/{your opc item's address}".

-Justin D

[andysibley]

Hi,

This is exactly what I'm doing on a large project.  ControlLogix 5555 processor via Ethernet to RSLinx and then to LV DSC 8.2.  See my earlier posting on communicating with RSLinx and some of the problems you're likely to face.  If you need more help then please ask!

http://forums.ni.com/ni/board/message?board.id=170&message.id=210031#M210031
Regards...Andy