peer-to-peer communication between PLC's ControlLogix

[greta]

Hello everybody,

I have two PLC’s ControlLogix and need to exchange some data peer-to-peer.
The data (about ten words from plc 1 to plc 2 and ten vice-versa) consist of time-critical data such as interlocks and setpoints, therefore I cannot/do not want to use Ethernet/IP explicit messages. On the other hand those data do not require ControlNet determinism. Also I do not want a ControlNet link just for this purpose cause each of the two PLC’s has already the following communication modules:
- Ethernet/IP for remote I/O purposes
- Ethernet/IP for Scada purposes
- DeviceNet for drives link

How can I exchange those data at a speed implicit-messages-like, exploiting the above networks?

Thks in advance.

 

[djs]

Hello;
As long as the Ethernet network between the PLCs is not highly loaded, implict messaging using producer/consumer tags works. I know, I have done it. A bonus you can also control the update interval for each tag.
Recommendation: place all of the tags to be transfered into a user defined structure. As long as this structure is less than about 900 bytes long, this will be the most efficient way to transfer data.

 

[BrooksWinchester]

An other way what works, since you have the Ethernet connection for your Scada system is to use the TOP Server with it's ControlLogix Ethernet Driver. It has something called a DX plug in that will let you use the server to transfer data from one device to another without actually interacting with the SCADA system.

The nice thing about this option is it gives you the ability to do it all over Ethernet and control the timing.

See

http://www.toolboxopc.com