Programming a PLC through VB

[Hassman]

Good point Keshik, I agree with the heartbeat analogy, I was thinking that I should have some kind communication check.

My big thing is communicating through the RTU protocol, you guys have provided me with some good content that I will review to try and setup a basic script to communicate. I'll report back in a bit and let you know how I'm progressing.

Thanks for your support as alway

 

[aemcgo0]

Go get this book, it goes through the basics of setting up direct communication with a Micrologix 1500, I think, through VB.

http://www.amazon.com/Home-Automation-Basics-Applications-Connectivity/dp/0790612143

A few years ago, 2005, I did a project where I had a bunch of cognex cameras talking to a Micrologix. The management of the plant wanted a way to data log directly from the station and tie this to a serialized barcode. So using the methods in here I was able to write a VB6 program to connect to the micrologix to see it's IO, Login to the Cognex Cameras to pull the image, and then use a USB connected barcode scanner to tie all this into a SQL insert statment.

Have to say I haven't used it since, as there are other, easier albeit more expensive than free, ways of connecting to a PLC. But for what I was doing here it worked like a charm.

aemcgo0

 

[Hassman]

Beat you to it aemcgo , I ordered a copy just yesterday, it might be old but frankly it is referenced so often that I knew it would be a great resource. Plus, I got a used copy for 12 bucks...doesn't get better than that!

 

[GeoffC]

I have done something similar
I wrote a vb.net application as an operator interface and used the .net application to log data to an SQL database
I used

http://www.modbusdriver.com/doc/mbusmaster.net/default.html

(or something similar) to provide the Modbus interface, saved a lot of heartache. Just google Modbus .net and you will find a lot of code and dlls available