Redundant AB CLX with Modbus conversion

[VicZA]

Hi Guys,

Maybe you have some experience with this set-up and can give me some pointers.

Project is to use an Emerson DCS to communicate (via MODBUS) with AB drives, E300, etc using a redundant system (communication channels A and B from the DCS).

We are looking using redundant CLX controllers to communicate with this setup. Is the only way to do this using a RED CLX pair with MVI modules in a 3rd rack? or could the MVI modules be placed in the two RED racks (as per attached picture).

Is there a better way to do this (maybe not using redundant PLCs) but guarantee two separate communication paths to the devices (channel A and Channel B)

Thanks
Vic

 

[Ken Roach]

The recommended and supported method is to put the MVI modules into a remote chassis.

The ControlLogix redundancy manager modules can't manage I/O modules or specialty modules, only EtherNet/IP, ControlNet, and CPU modules.

Why are you using Modbus/TCP for this interface ? Emerson is notorious for being unhelpful in troubleshooting third party interfaces, but this sort of connection is exactly what the Mynah VIMs are for.

Is this a DeltaV or an Ovation or something else ? Why do you think that you need separate communication paths ?

 

[VicZA]

The DSC is Ovation.

It has been designed that way, having two independent paths, A and B ... allowing for redundancy. If path A fails (for whatever reason) then path B takes over ... that's how it has been explained.

 

[Contr_Conn]

You can only put Processor, EN2T, CN2 and RM2 in redundancy chassis.
Any other modules will cause system disqualification.

Modbus must go into remote chassis