Communication with Modicon OPC Factory Server v2.5 via Visual Basic!


Thread Starter


I have set up Modicon OPC Factory Server v2.5 to communicate with a Modicon Momentum PLC!

I don't have a lot of experience with visual basic ... so i need some help on how to go about programming an interface to control (i.e read/write) the Momentum PLC inputs/outputs remotely over Modbus TCP/IP!

I need a fast and dirty method to do this, because...the project is only 2 weeks long!

Please give me some pointer ... or some visual basic examples that perform similar features!

Thank you very much for any help!
much appreciated!

Chad Markovich

I've not had a chance to look at the contents of the V2.5 OFS CD, but on previous releases (V2.0 & V2.2) Schneider Automation has put some VB source code examples for setting up groups & items, connections to the server, synchronous/asynchronous reads & writes, ... on the installation CD.

Chad Markovich
Application Engineer
Northwest Controls
[email protected]

Jeffrey Smith

I'm not sure based upon your wording in your question if you are trying to access the a PLC
directly over MB+ or if you are trying to create a simple OPC client to access data in the OFS

Jeffrey Smith
Director of Engineering
Cyberlogic Technologies, Inc.
Don't forget, if it's a I/O mommentum, that you have to write complete Output area to set Output values. The Item to manage output must be an array item.

Same for the imput.

Best regards
Hi Jeffrey...
Sorry about the confusion.

I want to create an application in VB to communicate with the PLC to read/write data from/to the PLC to control its IO's.
I'm not sure which method is better, commmunicate directly to the PLC or communicate with the OFS server? Please advise...thank you!

Sanjay Patel

Dear Friend

I have prepared OCX to communicate with any Modbus device through serial port and working on application which receive the data from serial
port and send the data on ethernet to server. Please give me some more information so I can help you.


Sanjay Patel
System Analyst
Tectona Soft Solution (P) Ltd.
mobile no. +91-98240-09450