RSLogix5000 - Readng I/O on Ethernet

[Ken Roach]

I was intrigued by this and set up a demo system at my desk:

RSLogix 5000 v13.04

Owner Controller:
1756-L1 v13.27
1756-ENET/B v2.7 IP Address 192.168.1.7

Listener Controller
1756-L1 v13.27
1756-ENBT/A v3.9 IP Address 192.168.1.101

I/O Adapter
1794-AENT v2.12 IP Address 192.168.1.94
1794-IB16
1794-OB16
1794-IE4xOE2

I set up a program called "FLEX_Owner" and another called "FLEX_Listener".

The Owner program has a "None" connection type for the 1794-AENT itself, and Module Connections for the three I/O modules. The discrete modules are at 50 ms, the analog at 100 ms RPI.

The Listener program has a "Listen Only - Data" connection for the 1794-IB16 and an "Listen Only - Input Data" connection for the 1794-IE4XOE2.

Put 'em together, download, and the FLEX_Owner program has happy I/O connections and data's coming through.

But the FLEX_Listener... has "Module Fault (Code 16#0118)Module Configuration Rejected: Format Error" in the Connection tab for both connections.

But wait... the whole point of the Listen Only connection is that there isn't supposed to be Configuration data going out to the 1794-AENT for these modules.

 

[Ken Roach]

Here's the punchline; I think there might be a bug in this particular combination of devices. When I set the Electronic Keying for both modules to either "Compatible Module" or "Exact Match", in the Listening controller, the error goes away and I get a running Listen-Only I/O connection. The red LED on the 1794-AENT goes away only after a power cycle of the AENT after this mis-configuration.

Why would a *more* restrictive keying option make this work ? My theory, backed up by a little snooping on the EtherNet/IP traffic, is that the 1756-ENBT sends connection request information to the 1794-AENT when you select "disable keying", and the 1794-AENT rejects that connection information. When you select "exact keying" or "compatible module" then RSLogix 5000 and/or the 1756-ENBT do not send connection request information, which is what they are supposed to do with a listen-only connection.


I will post my two example configurations.

 

[Operaghost]

Just out of curiousity, why would you have selected to disable electronic keying in the first place?

To me, the natural choice is to use the default "compatible module" setting. I am just wondering why you would (in this case, not "why would you ever...") choose to disable keying.

I have seen a similar conflict with standard 1756 I/O cards so this is not an issue unique to the Flex platform. I had completely forgotten about it until I read your results.

In my case though, the wrong card was in the I/O config and disabling keying was a temporary fix that worked fine for the owner controller but not for the listen connection.

Interesting.....

OG

 

[RSL]

I always run on "compatible module". I did have to disable it once to resolve a firmware/hardware issue on a replacement for a failed card. It was a temporary fix too.

Perhaps this "bug" is intentional. This keeps the end user honest when configuring a listen only request which by default must be at least a compatible module to work properly? I know it's a stretch at best.

RSL

 

[WebRanger]

To be Continued

Thanks to all for the input. No time today to act on it, I was fire fighting...
Ken, I think I saw that same message code you encountered with the module fault, but I don't remember having good date. I appreciate the time you took and I looked at your files.
To be honest I am still intrigued by the concept of "Producer" and "Consumer" tags and want to read and digest that well. I think this all ties together. I had the blinking Module Status led also.
I hope to have results to post on Monday, right now I have to go sell my house.
A great Weekend to all of you!

Webranger Jim