Installing prosoft modbus card into a redundant CPU IO Chassis 1756-L61 controllogix

[anthony09]

1) I am currently trying to integrate a Prosoft MVI56E-MCM Module into a 1756-L61 CONTROLLOGIX5561 that is a redundant system (CPU is redundant and a control-net module is used to connect the IO chassis)
Actions carried out:
*I connected the Prosoft MVI56E-MCM module to the base rack and it communicates but the downside is that this disables the redundancy of the CPU and I don’t want to disable it.

* I then tried connecting it to the IO rack. I get the information (WAITING FOR PROCESSOR COMMUNICATION) which means it’s not communicating.

PS: it’s an existing installation.

 

[Contr_Conn]

You can’t have this module in processor chassis in Redundant systems. This is the basic rule of redundancy and I recommend to read redundancy manuals first.

You can have it I/O chassis, but you must add it in I/O configuration, and re-schedule Controlnet. You may run into the situation that the amount of data may not allow you to schedule with selected parameters. If you never used ControlNet, please hire someone who knows it. It’s not simple.

 

[anthony09]

You can’t have this module in processor chassis in Redundant systems. This is the basic rule of redundancy and I recommend to read redundancy manuals first.

You can have it I/O chassis, but you must add it in I/O configuration, and re-schedule Controlnet. You may run into the situation that the amount of data may not allow you to schedule with selected parameters. If you never used ControlNet, please hire someone who knows it. It’s not simple.

Thank you for your quick response.

Due to time constraint i might need to do the reschedule controlnet myself. please can you give my pointer or guidelines so i can get myself up to speed.

 

[Contr_Conn]

I don’t want to give you any advice because I did not touch ControlNet for 5+ years.
You can read manuals and tech notes.
You will need RSNetworks for ControlNet, version should be compatible with your controller version or higher. And as I recall - there is no “Undo”

 

[Contr_Conn]

And it looks like your ControlNet is not done correctly. I see that you have redundant coax cable connected Directly to modules without T-Taps and terminators. This is illegal.
Also ControlLogix redundancy requires at least 4 ControlNet nodes.
You have only 3.
It’s funny that someone put redundant power supplies but did not follow basic network tools for resiliency.

And how you are connecting your computer? The RJ45 on 1756-CNB module is not Ethernet, this is CNET access port. I see Ethernet cable plugged into CNB... This will not work.

You will not be able to schedule ControlNet via controller serial port.
So get qualified help.

 

[Ken Roach]

Missing batteries, disqualified Secondary, Ethernet cable plugged into the NAP on the ControlNet, no ControlNet taps... almost everything illustrated in those photos is wrong for a ControlLogix, let alone a Redundant one.

If this system controls a process that is important enough to need a Redundant controller, the professionally responsible thing to do is hire someone who knows how ControlLogix Redundancy works, or is willing to read and understand the basic manuals.

Is this a new system ? Has it been running for a few years ?

Start by figuring out where the ControlNet taps went, and plug into the Ethernet port of the 1756-ENBT. Unplug those cables from the RJ45 jack on the ControlNet modules; it is for an old ControlNet network access card, not Ethernet.

 

[anthony09]

And it looks like your ControlNet is not done correctly. I see that you have redundant coax cable connected Directly to modules without T-Taps and terminators. This is illegal.
Also ControlLogix redundancy requires at least 4 ControlNet nodes.
You have only 3.
It’s funny that someone put redundant power supplies but did not follow basic network tools for resiliency.

And how you are connecting your computer? The RJ45 on 1756-CNB module is not Ethernet, this is CNET access port. I see Ethernet cable plugged into CNB... This will not work.

You will not be able to schedule ControlNet via controller serial port.
So get qualified help.

Thanks again. This is an existing system. All the point raised are valid and i have to insist on all these fixed. I have been communicating via the CPU 232 port. i just need links to manuals that can help me understand the setup and offer solutions to the clients.

 

[Contr_Conn]

You can’t schedule CNET through RS-232. Simply does not work.

Need a pair of 1756-ENBT in controller chassis or at least one in I/O chassis.
But you must fix cabling (T-Taps, terminators, etc. ) before doing anything else.

And unplug ethernet cable from CNB before you damage something else.

Here is user manual for old Redundancy:
https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

 

[anthony09]

Missing batteries, disqualified Secondary, Ethernet cable plugged into the NAP on the ControlNet, no ControlNet taps... almost everything illustrated in those photos is wrong for a ControlLogix, let alone a Redundant one.

If this system controls a process that is important enough to need a Redundant controller, the professionally responsible thing to do is hire someone who knows how ControlLogix Redundancy works, or is willing to read and understand the basic manuals.

Is this a new system ? Has it been running for a few years ?

Start by figuring out where the ControlNet taps went, and plug into the Ethernet port of the 1756-ENBT. Unplug those cables from the RJ45 jack on the ControlNet modules; it is for an old ControlNet network access card, not Ethernet.

Thanks for the suggestions will have to get all those information.
It is for an existing system and has been running for years which is maybe why the batteries are down. please kindly share links to any information i will need to understand the system.

 

[anthony09]

You can’t schedule CNET through RS-232. Simply does not work.

Need a pair of 1756-ENBT in controller chassis or at least one in I/O chassis.
But you must fix cabling (T-Taps, terminators, etc. ) before doing anything else.

And unplug ethernet cable from CNB until you damage something else.

Here is user manual for old Redundancy:
https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

Thanks will stick to your suggestions and thread lightly

 

[bevanweiss]

Have you googled?

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um535_-en-p.pdf

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/61501

 

[anthony09]

Have you googled?

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um535_-en-p.pdf

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/61501

Thanks. Did some googling but wanted more help in case i was missing any vital information.

 

[bevanweiss]

You might want to consider an alternative Modbus card also
https://www.prosoft-technology.com/...e-MVI56-xx-modules-be-placed-in-a-remote-rack

Whilst the card is supported in a remote rack, the ControlNet data capacity is limited, so you might run into issues with overall performance, and the redundancy aspect will only complicate the situation.

The ideal scenario would be to have a redundant Ethernet/IP ring, which you could then put the MVI56E into an Ethernet/IP connected rack. But to get there from where you currently are would be a big investment. Albeit swapping out ControlNet for Ethernet/IP can make for a more available system anyway, so depending on the process, it may be financially prudent to consider.

 

[Contr_Conn]

I forgot to mention that scheduling ControlNet will require controller to be switched to program mode. If system is running process this may not be possible.