how to connect nano plc through opc

[kittubec]

hi,

I am an engineering student. In our college we have ge fanu nano 10 plc.

we have a labview 8.5(registered version.). I want to control parameters through labview.

please help me in this issue.

         waiting for replies........ 

[muks]

Have you used VISA functions?

[kittubec]

I am sorry.I didn't hear anything about it. so will you please let me know what is it clearly?

I somewhere heard that nano plc can not act as opc server if opc communication has to be used?

give me a link about these visa functions too...........

sorry for my ignorance........ 

[muks]

VISA

[kittubec]

I read that all serial I/O operations can be carried out through nano plc.

Is it possible to access the internal registers of the plc through these VISA functions?

If Yes, & if possible give me a small example.........

[Ryan.S]

To make the connection, the OPC Server is an option. LabVIEW itself doesn't have the OPC Server for the PLC. LabVIEW DSC module has it.

If the PLC supports Modbus protocol, you can use the LabVIEW Modbus library to make the connection. The library can be downloaded on NI website, but not officially supported.

The VISA is low level driver. You can use the VISA to do the serial port communication. But VISA itself doesn't have the PLC driver. If the PLC communication protocol is not complicated, you can implement the protocol by VISA. For example, send some kind of command by VISA through the serial port to get data from PLC. But you should know the protocol, and hope it's not complicated.

[kittubec]

You are saying that I have to go for complex programming in plc if I use VISA functions and it will be easier if I use OPC through DSC module.right?

are there any other drawbacks for VISA ?

I am interested in it........ 

[unclebump]

You don't have to do any programming in the plc for labview to read/write the data. You need to know the protocol for the port that connects to the plc. Then you have to write labview code to duplicate this protocol. Are you talking to a serial or etherent port on the plc?? Look for a communications manual for the nano plc that details data transmission. Look at chapter 25 in this manual

http://support.gefanuc.com/support/resources/sites/GE_FANUC_SUPPORT/content/live/DOCUMENT/0/DO458/en...

Drawbacks to VISA. It will take unique commands to read/write data from the controller. Possibly unique commands for each datatype that you want to read. I've never used the nano plc. Looks like the nano plc has a serial port on it, unless you have an option module described in chapter 14.

Since the device uses the serial port, you could use portmon to reverse engineer the protocol. Find a demo program that talks to the nano plc, then use portmon to watch the code as it is being transmitted.

Message Edited by unclebump on 12-04-2009 10:46 PM