Retrieving data from PLC


Thread Starter


I wanted to establish communication through RS232 port between PC and PLC ( SpA Plc's)

We have developed front end in QNX - Photon(Application builder)

Can some one pls enlight me on how to retrieve data from PLC. what are the necessary things i should know ?
It is not clear what PLC you are trying to talk to.
Anyway the information you will need is the cable details between PLC and PC for RS232 comms.
The PLC softaware seetings like PLC address, baud rate etc..which can be determined only if you use PLC specific software for configuration. Interms of SCADA you will require to have a driver that is specific to the PLC compatile with the SCAD software. Else you may use a standard Modbus driver if PLC supports modbus ..
The PLC manual will be of help for the same.

Zeljko Fucek

First, read the QNX Application Builder manuals ... All Photon Application Builder versions come with decent documentation and examples of Inter Process Communication (IPC) with message passing between a non-Photon
process and your Photon application. Your non-Photon process is the driver, it can poll data based on time or interrupt, any way you like it
(or design).

The message can send up to 64k of data (your choice of form) in few milliseconds intervals, synchronously.

For more information, I suggest news://comp.os.qnx.

Good luck,

Zeljko Fucek