What are some recommendation to keep existing I/O but transition to Control Logix platform? Can we use controlnet? Any other networks recommended over controlnet? How about DH/RIO module?

 

We have done this with both PLC5 (1771) and SLC5 (1746) hardware using the DHRio modules with the relative ASB modules. Using the racks on RIO is quite simple, especially if you have used RIO before. Only things to watch is that some modules will not work, but generally you would replace them with the 1756 version anyway and any speed issues with fast IO devices.

We use ControlNet for ControlLogix rack and occasionally processor to processor communications. DeviceNet for IO on the ControlLogix has worked quite well for us too. Our preference for Scada has been to use Ethernet, but at this stage we still use standard Panelviews on DH+. When we take the plunge to use Panelview Plus or VersaView, we will go with Ethernet there.

Cheers,
Trevor Ousey

 

To keep your I/O you can use existing Remote I/O using 1756-DHRIO as a Scanner or change 1771-ASB to 1771-ACN(r)15 to use controlnet. Both work fine.

Evandro C Vizicato
[email protected]

 

I would recommend against using the DH+/RIO module. Convert to ControlNet if possible. The ControlLogix can only handle 12 simultaneous block transfers (BTW/BTR) at one time per DH+/RIO module and I does not cache them like a PLC5. If your system has a lot of analog or specialty I/O that uses block transfers this can really slow down your system.

Good luck,

Michael E. Crossman
PLCs Plus International, Inc.
http://www.bkppi.com

 

We have multiple PLC5 Processors with Flex I/O. When the time comes we will remove PLC5 and install Control Logix and continue to use Controlnet. Control Logix is very flexible with networking. We have installed Control Logix platforms without processors to use as network gateways. You can jump from Ethernet to Controlnet to DH+.

 

I suggest to use the 1771-ACN15 Controlnet adapter on your PLC5 rack (instead of the processor) and the 1756-CNB Controlnet bridge on the ControlLogix platform.

 

If you are planning on controlling very many 1776 IO points in a rack then ControlNet is the only way to go. It is less cumbersom that working with the data size and speed restrictions of DN or DHRIO.