Controlnet Setup using RSlogix 5000

I have 4 PLC racks.
Rack 1 = PLC1 (1756-L1), Control Net 1756-CNBR, & Redundancy Module 1757-SRC

Rack 2 = PLC2 (1756-L1), Control Net 1756-CNBR, & Redundancy Module 1757-SRC

Rack 3 = I/O modules , with Control Net 1756-CNBR
Rack 4 = I/O modules , with Control Net 1756-CNBR

This setup gives hot standby.

I have the taps, coax cable, and termination resistors in place.

I need help setting up the control net to see the I/O. Can anyone shed some light? Descriptions of steps would be helpful.

Also I already configured the control net node address.

Rack 1 = node 1
Rack 2 = node 2
Rack 3 = node 3
Rack 4 = node 4

There are really only a handful of steps to schedule a ControlNet segment.

1. Download the RSLogix 5000 program, which includes I/O module and communication connection configurations, to the Primary controller.

2. Open RSNetworx for ControlNet software and go online with the network.

3. Click the "enable Edits" checkbox. Wait for the browse to complete. Click the "Save" button to schedule the network.

You have a handful of configuration problems with your network addressing. The 1756-CNBR modules in the controller chassis cannot be the lowest numbered nodes on the ControlNet. Your two I/O chassis should be Node 1 and Node 2, while the 1756-CNB modules in the controller chassis are Nodes 3 and 4.

Also, you configure the 1756-CNB modules in the controller chassis as the same ControlNet node numbers; the rotary switches on both of them should be set for Node 3. The 1756-SRM redundancy modules will take care of managing the node numbers for the Primary and Secondary chassis.

Edit: 1756-L1 controllers do not support redundancy and have been obsolete for at least five years.

With any redundancy system, you must read and understand the ControlLogix Redundancy System User Manual as well as the Release Notes for the specific Redundancy version you are using. You must adhere to a very specific set of hardware and firmware compatibilty rules that are very clearly explained in the Release Notes for redundancy to work.

Several useful user manuals:

ControlNet Modules in Logix 5000 Control Systems
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/cnet-um001_-en-p.pdf

ControlLogix Redundancy User Manual
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

ControlLogix v8 Redundancy System Release Notes
http://literature.rockwellautomation.com/idc/groups/literature/documents/rn/1756-rn612_-en-e.pdf

ControlLogix v11 Redundancy System Release Notes
http://literature.rockwellautomation.com/idc/groups/literature/documents/rn/1756-rn582_-en-e.pdf

ControlLogix v13 Redundancy System Release Notes
http://literature.rockwellautomation.com/idc/groups/literature/documents/rn/1756-rn608_-en-e.pdf

A second thought; Upon further review, I do not think the 1756-L1 controller was ever part of a Redundancy system; version 8 was the first redundancy release and it started with the 1756-L55.

Did you buy this hardware used ? Are you re-commissioning an old system ?

Sorry the processor part # is 1756-L61

Ken, I know this is an old thread, but I have a question in relation to it.

Where you state, "The 1756-CNBR modules in the controller chassis cannot be the lowest numbered nodes on the ControlNet.", does this relate only to redundant hot-standby systems?

If you had a single CPU rack, with 1 CNB module and, say, 2 remote racks, does this remain? Or can the CNB module in the CPU local rack have the lowest node number?

Thanks,

Robbie

The "originator module cannot be the lowest node number" rule is specific to ControlLogix Redundancy with ControlNet.

It has to do with the fact that the two 1756-CNB(R) modules momentarily both disconnect from the network and reconnect with new MACIDs. There needs to be at least two devices, one of them with a lower node number than the redundant 1756-CNB(R)s, in order for the ControlNet network to keep running through the redundancy switchover.

There are no restrictions or rules for the node number of the 1756-CNB(R) that resides in the chassis with the CPU on a non-redundant system. It's usually Node 1, but it doesn't have to be.

Thanks for the swift response, Ken.

Tags

Hello, I know it is an old topic and hope i get an answer...
Is there any way of generating controler tags from the RSNetworx configuration file. Something like DeviceNet configuration tool.
In offline mode.

Thanks