AB 1769 - Code 16#0204 issue

[sparkytex]

Hello All,


Trying to troubleshoot a message instruction that’s always worked between two compact logix processors (Both 1769 L32E). I noticed that the message instruction is on a periodic scan rate of 100ms, and there’s an enable bit addressed to the very message instruction to enable it. I noticed the enable XIO bit was always off. When I opened up the MSG instruction, the enable and enable waiting in the configuration Tab was staying on. Obviously this MSG instruction is having issues.

Then I realized under the expandable IO tree on the left side of RSLogix under the 1769-L32E Ethernet Port “Port Hardy” is has a little error beside it and that’s when I opened properties/connection and I see the module fault - Code 16#0204 error. I’ve tried changing ports, restarting networks switches, and even PLC processors with lo luck. It’s strange that there would be a connection issue when I can go online with both processors and ping the controllers with no issue. I’ll tried to attach some pictures for better explanation but this site doesn’t like to upload I phone Photos it seems.

Thanks for any help

- Tex

 

[Ken Roach]

I think you're going to have to screenshot and post the logic that triggers the MSG instruction, and explain how the 100 ms periodic trigger functions. You may need to take screenshots, save as *.PNG, and post from an ordinary non-iPhone browser.

You should never manipulate any of the MSG control tag status bits with logic except for the .TO timeout bit. Any logic that turns on or off the .EN or .DN bits should be reconsidered. It sounds like your logic might be "fanning the trigger" and re-triggering the MSG as fast as possible.

Error code 16#0204 is a general connection error, that most commonly occurs when a device is actually unplugged from the network.

If you can get online with both CompactLogix and they're on the same network, this shouldn't be too difficult to sort out.

The 1769-L32E had a relatively small Ethernet network capacity so it's possible that extra HMI stations or new engineering workstations that are browsing it with RSLinx, or even network management activity that is taking up TCP connections, has changed the network conditions from how they were back when everything worked correctly.

 

[sparkytex]

Ken,


Here's a few pictures to clear up what I am talking about. As you can see these MSG instructions only have an XIO enable bit Infront of them. What I meant was the entire Task was on a periodic 100ms scan. I currently have both programs from both processors loaded and online with my laptop. Like I stated I tried rebooting both PLC's, changing patch cords, bypassing network switches, anything I can think of. Looking more into it, every message instruction on this specific PLC is doing the same thing and not working. This is definitely getting down to crunch time and these need these motors working. Problem is we can't just slap them on Hand as they need to be run of the controls in the PLC program or the guys will be here all night.

 

[sparkytex]

one more picture

 

[sparkytex]

I also just took down both PLC's and all network switches, the entire automation/SCADA system and rebooting it at the same time and the messages are now working but the error on the one PLC remains. Kind of a head scratcher, not sure why they just decided to work lol

 

[Ken Roach]

Thank you for that context and details !

So you're online with the 1769-L32E controller named "ABJ_CompactLogix" at 192.168.24.10.

That controller has another 1769-L32E in its IO tree, named "PORTHARDY_Controller".

And the ABJ_CompactLogix is also intending to execute on Tag_Read and one Tag_Write every 200 milliseconds.

The symptoms you are seeing appear consistent with the PORTHARDY_Controller CompactLogix not being connected to the network. That's why there is a 16#0204 connection failure and the yellow triangle in the I/O tree, and why the MSG instructions are always "Enabled and Waiting".

What confuses me, though, is the screenshot showing the port statistics for the LocalENB interface on the ABJ_CompactLogix controller. They show zeroes even for the counters that should be incrementing normally with every communications transaction.

In addition, there is a "Faulted" status indication for the LocalENB daughtercard showing on that screen, but no yellow triangle in the I/O tree, and of course you're online through that interface.

So that's... weird.

Are there any Produced/Consumed Tags in either project ? Try filtering the Controller-Scope tag database. The data exchange between the controllers can likely be done more efficiently with P/C than with MSG instructions.

But first you do have to figure out why there's a connection failure to PORTHARDY_Controller from ABJ_CompactLogix, and why the port on ABJ_CompactLogix shows that fault when you try to look at the diagnostic counters.