Compactlogix to PLC-5 Communication...

How can I read from Compactlogix to PLC-5 through ethernet (same network). I'm using the MSG instruction but PLC-5 won't read a 'tag' from Compactlogix, right? Thanks!

You will have to use the mapping feature of the RSLogix 5000 software

I map the tag in the Compactlogix - Address 0 with Tag 'example'. On the PLC-5 I use a MSG instruction but it wont take 0 as the target address.

No, you have to map it to something that the PLC5 understands. For example a 7 in the mapping dialog could refer to an integer register in the PLC5, like N7. You would config the MSG to read from N7. The tags in the compactLogix would have to be of a type the PLC5 understans too, like in theis example an interger. The tag of the CompactLogix side would probably be an array of integer types. What's the 0 for? If your referring to an Output, you can't do that. The same for Inputs.

See doc below.

I used DH+ messaging using MSG with a controllogix and plc-5; i think its the same just doing some changes:
1. In MSG block (using ur logix5000 program)...go to CONFIGURATION change messange type to: PLC 5 type write.
2. Source element B3_30[0] (this is the start tag i used for).
3. Number of elements 10 (cause gonna write to plc-5 b3_30[0] to b3_30[9].
4. Destination elements b3:30 (so gonna write to plc5 b3:30 to b3:39)
5. In COMMUNICATION... path gonna look for ur controller PLC-5.
6. In comm method u have to use CIP i think... cause i used DH+.

Well im always writing and reading bits so i used "MSG".EN to alternate everytime.

Hope gonna work.

cintronfamily said:

How can I read from Compactlogix to PLC-5 through ethernet (same network). I'm using the MSG instruction but PLC-5 won't read a 'tag' from Compactlogix, right? Thanks!

Click to expand...

There is no way a PLC5 will "read" a ControlLogix tag, it just doesn't understand the much newer ControlLogix tag database concepts, and RA will never put that functionality into the PLC5.

Instead, they have provided a mechanism in the ControlLogix that provides compatability with the older systems like PLC5 and SLC PLCs.

This mechanism allows the PLC5 or SLC to "believe" it is reading a data-table address from another PLC5 or SLC. And that is where the "Map PLC5/SLC Messages" comes into play in the ControlLogix project. (Find Map PLC5/SLC Messages" under the "Logic" menu).

Example :-
For simplicity, I will describe reading a ControlLogix INT array called CLX_Data, which will be 20 INTs in length.

The PLC5 message will have to be set-up to read a valid PLC5 data-table address, e.g. N120:0 length 20

The ControlLogix will have to have added to the "Map PLC5/SLC Messages" the following association - File Number = 120 ControlLogix Tag = CLX_Data. Then whenever the ControlLogix sees a message for read or write access to N120, it substitutes CLX_Data to access the data. Therefore, if the message tries to read N120:6, length 3, the mapping supplies the data from CLX_Data[6], length 3

Personally, I think that it is easier to let the ControlLogix handle data-transfers to/from legacy PLCs and SLCs. No mapping is required, the message configuration directly specifies the source/destination data-table addresses.

Mickey said:

See doc below.

Click to expand...

Jeez, I never knew that Mickey !!

daba said:

Jeez, I never knew that Mickey !!

Click to expand...

I don't even remember where or when I got that document. I have not tried it as I'm not a ControlLogix/CompactLogix user.
So I don't know if it works or not.

Mickey I got that off MrPLC and yes it does work. I did it after the plant engineer hired 5 different firm to figure how to do msg between our mission critical equipment.we where out if I/O so discrete was out and we couldn't stop production for 6 months. I found this and it worked and saved the day.