1756-CN2R Different Series

Hi all,

I have to replace a faulty module of 1756-CN2R Series B for IMCS System. The system has 2 redundant rack which I believe for software redundant since there is no 1756-RM2 module available. The faulty module located in secondary rack. However, I plan to replace the faulty module with 1756-CN2R Series C (the only spare module available at site) which is different series with the existing one.

My question:
Do I need to re-schedule the ControlNet network once I replaced the faulty module with 1756-CN2R Series C because my client don't want to stop their production?

Thanks in advance

It probably can't hurt to try; set up the module for the correct Node Number using the rotary switches, and see if it accepts the Keeper and schedule information from the rest of the system.

"Software Redundancy" is very, very tricky. A-B has never recommended it, and only supports it in some very limited circumstances.

If you have a critical system that uses some kind of home-built pseudo-reundancy mechanism, I very strongly recommend that you get the OEM to consult before attempting to modify it.

Ken Roach said:

It probably can't hurt to try; set up the module for the correct Node Number using the rotary switches, and see if it accepts the Keeper and schedule information from the rest of the system.

"Software Redundancy" is very, very tricky. A-B has never recommended it, and only supports it in some very limited circumstances.

If you have a critical system that uses some kind of home-built pseudo-reundancy mechanism, I very strongly recommend that you get the OEM to consult before attempting to modify it.

Click to expand...

Hi Ken, thanks for your reply. Mean no need to re-schedule the ControlNet network? Just need to set the node number rotary switch as per old module right?

The principle is that the ControlNet modules will receive the current configuration and schedule from the "Keeper" node.

As long as you set the Node Number correctly, the worst thing that's likely to happen is that the secondary chassis doesn't receive that data and go into operation.

Do you know what version of controller firmware and 1756-CN2R/B firmware is already running ?

It's possible that the existing controller and 1756-CN2R will not connect to the new one because of firmware compatibility or electronic keying issues.

Ken Roach said:

The principle is that the ControlNet modules will receive the current configuration and schedule from the "Keeper" node.

As long as you set the Node Number correctly, the worst thing that's likely to happen is that the secondary chassis doesn't receive that data and go into operation.

Do you know what version of controller firmware and 1756-CN2R/B firmware is already running ?

It's possible that the existing controller and 1756-CN2R will not connect to the new one because of firmware compatibility or electronic keying issues.

Click to expand...

The existing firmware is 1756-CN2R Series B F/W: 20.009. In the logic, for 1756-CN2R Electronic Keying: Compatible Keying