View Full Version : PLC communication

March 24th, 2005, 11:06 AM
Hi Everyone,

I'm a student who is working on PLC communication under visual basic.NET . I already made an HMI in order to get info and status from the plc, and it was wotking fine under rsLinx.

My boss wants me to write my own driver, in order to etablish a communication without RSLinx.

I just want to know which kind of protocol do I have to use, just get a few more informations.


March 24th, 2005, 11:20 AM
I'm making some assumptions here, but:

Since you are using RSLinx as a comm server I assume you are communicating with an Allen-Bradley PLC. Since you are a student I will further assume the plc is either an SLC or Micrologix and you are communicating via RS-232 (these are the least expensive options).

IF all of this is true you are communicating using a protocol called DF1. Take a look at this link:
for the DF1 command set reference.

Have fun.

March 24th, 2005, 11:35 AM
Thank you very much, it seems to be a little complex, but the documents you gave me is going to help me a lot !

And you were right, i'm using a SLC, communicating with RS-232 !!

Gerry M
March 24th, 2005, 01:24 PM
Just curious, why not use RSlinx? You already have it.

March 24th, 2005, 01:31 PM
Follow this link http://www.plctalk.net/qanda/showthread.php?t=10339 It has a free:beerchug: DF1 Driver for .net

March 24th, 2005, 02:12 PM
Thanks for the link :nodi:

Our clients have to buy a liscence for RSLinx too, so we want to cut this expenditure off, and make our own communication driver.

thank you for help !!