MicroLogix to CompactLogix communications

Is it possible to have a MicroLogix 1400 read information from a CompactLogix address?

I've done it the other way many times. Reading the data tables of a MicroLogix plc with a CompactLogix, very simple.

But I'm looking through the MSG instruction in RSLogix 500, and am not sure which if any of these communications commands will work, or if I have to structure the data in the CompactLogix a certain way.

Edit: The plan is Ethernet communication, if that makes any difference

Thanks

See attached file

Hope this will help you.

You'll have to map some addresses in the Compactlogix to registers the 1400 can read and write to. In Logix/Studio 5000 this option is found under the "Communications" menu and does require a download.

widelto said:

Hope this will help you.

Click to expand...

Somewhat, but that Step 3 "Target Device". The Data Table Address field (if it's a 500CPU Read that is used?). That's the part that wasn't very clear.

bjh said:

You'll have to map some addresses in the Compactlogix to registers the 1400 can read and write to. In Logix/Studio 5000 this option is found under the "Communications" menu and does require a download.

Click to expand...

Ok, I think I found what you are getting at. Is it the "Map PLC/SLC Messages..." option under the Logic menu?

So I can just make the CompactLogix mimic a SLC and use a 500 Read/Write in the MicroLogix to those addresses?

See attached file

Tharon:

This is an example of mapping and messaging.
It's CLX version 13 but you can convert it to later version.

Bill

Tharon said:

So I can just make the CompactLogix mimic a SLC and use a 500 Read/Write in the MicroLogix to those addresses?

Click to expand...

Yes. I like to use an array of INTs. Say you have an array called "Micro1400_Read" with a size of 256 mapped to the SLC 70 datafile. Then the ML1400 can do a message read of N70:0 and up which will map to Micro1400_Read[0], N70:1 will be Micro1400_Read[1] and so on.

Ok. I understand it now. Thanks.

One of those things where I didn't even know where to start looking. Didn't know about the PLC5/SLC Mapping function of the Compact/ControlLogix.