1761-net-eni

Our company has many of Rockwell's beloved NET-ENI modules to get SLC 5/03's onto our network. They have the issue of faulting out if more than 3 devices try to communicate with them. I've heard there is a way to send a message to the module from the PLC to reset them using a MSG instruction. It is described somewhat in the user manual 1761-UM006E but not in enough detail for me to figure it out. On page 4-13 it describes using a 485CIF write (aka a PLC2 unprotected write) to node 248 for save/reset. Has anyone done this before?

In my experience with the 1761-NET-ENI it was not uncommon to use up the number of available connections and cause communications issues some of which would only clear up with a power cycle. I never went so far as to try to reset one with message logic.

I always preferred the Digi-One IAP for this application since it never seemed to freeze up, but would just get slow if you tried to do more with it than the serial port bottle-neck would allow. We replaced all the NET-ENI modules with the Digi-One IAP HAZ at a previous employer one by one as they failed or gave us trouble.

We used the HAZ model due to the horrible environments some of them were going into (extreme hot and cold and high vibration).

I've done this on a ML1000 that was connected via WiFi and particularly problematic. You'll need something to trigger the MSG instruction and in my case I used S:1/7, the Comms Active bit. Not sure what bit you'd choose in your processor. This took two rungs.

First rung triggers a timer. In my case, I have it set to 2 minutes.
XIO S:1/7 TON T4:6 1.0 120 0

Second rung is the MSG instruction triggered by the timer /DN bit.
XIC T4:6/DN MSG WRITE 485CIF N7:0 N7:10 248 0 1 0

N7:10 contains a 1.

Change your control block, timer numbers, and data table address to suit your program.



Shawn