AB Produce/Consume - V24/V28

Issue: Not able to setup produce/consume tags between two controllogix PLC'c on different sub-nets.

Background: PLC 1 is a controllogix running V28, PLC 2 is a controllogix running V24. Since the two PLC's are on different sub-nets, UNICAST settings are applied to the consumed tags on both ends. PLC 2 is working as expected, PLC 1 (V28) is not.

When looking at PLC 1, the producing PLC 1 is flagged with an error - unicast/multicast connection not supported (error code is 16#0108).

"Allow Unicast Consumer Connections " option is selected at both ends.

Question: With the settings the same on both PLC's, the only difference being the controller version - what could be causing this issue?

The only time I've ever heard of Unicast support mismatch being version-dependent is if one controller is prior to v16 and doesn't support unicast.

Try power cycling or disconnecting completely. This really does sound like the "Allow Unicast Consumer Connections" feature is not enabled correctly.

Did you tick "use unicast connection" in your consumer tag, as per page 27?

http://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm011_-en-p.pdf

Yes. That was a requirement when we separated the network into different sub-nets.

Are you running redundancy on V24? Or at least redundant firmware 24.052?

Both plc's have partners since this is a safety application.

Please confirm; are these GuardLogix with Safety Partners, or are they ControlLogix Redundancy with two controllers and Redundancy Modules ?

Are the Produced/Consumed tags normal tags or Safety tags ?

Plc's are indeed Guardlogix and tags are controller scope safety tags. RPI settings for consumed tags match the safety routine RPI.

Just to close up this issue; the problem was a miss-configuration on the producing PLC. The producing tag was not marked to allow unicast connections.

Problem solved.