L71 to L33ER Connection

Good Morning Folks.
I have a little issue with a Produced Consumed set up between an L71 V30.11 and an L33ER V30.14.

I have set this up many times over and over through our facilities using the very same 88byte UDT every time. I copy it from 1 PLC to the next.

So upon setting up both projects to look at each others PLC I noticed a connection error right away. So I went over everything, as usually its just a typo or configuration error. I deleted the processors and tags and started over, a couple times. On the L71, I get the yellow triangle on the I/O tree for the L33ER and on the L33 I/O tree I have a yellow triangle on the L71 processor but not 1756-ENBT module.

So, in further efforts. I set the controllers up to see each other without the prod/con tag. They are ok now with no errors. I can look at the properties and status of the other controller in each project and all seems ok.

Now, I went to the L71 and added 1 single produced tag of my usual UDT type. I set up the L33ER as the consumer, copy and pasted the tag straight from one project to the other, no mistake! Upon putting it all into run mode, I now see that the L71 is not showing any errors, but the L33ER has a connection error on the processor. It code #16031e Cannot Consume Tag.
(This error is suggesting that the producer tag is already at its max number of consumers as defined on its properties. However the L33 is the only consumer)


Now the odd part...... The connection comes and goes. I can change a value in my L71 on my produced tag and it will change in the L33, maybe immediately, or after a few seconds when the error clears. Then I can send more values, until the connection flashes off again with he resulting error. It dropping in and out a few times / minute.

In the L71, my Modual Definition for the L33 is set to "Disable Keying" and Connection is "None". My produced tag here I have tried to "Provide Default RPI for Consumer Out Of Range" at 10ms.


Now looking at the module definitions in the L33 for the L71 I have:::

1756-ENBT Rev4.001
"Disable Keying"
Connection is "None"
Time Sync "None"
Chassis Size is 6
In slot #3


The 1756-L71 In slot 0
Rev 30.
There are no configurable Parameters further than this!


In my L33er Advanced Properties I have clicked "Allow Consumed Tags To Use RPI Provider by Producer"


I should add, not that I think it has any bearing on the situation, that my L33ER is on the network through the NATR module. It hasn't been an issue for me as I use them on the regular with no issues before.

Any thoughts on this folks?
I'v set up this similar scenario many times and never run into this. However, normally most of my projects are Compact Logix to Compact Logix though.

Any advice would be appreciated.

Thanks

Just to add to this.


I have just successfully set up a Producer Consumer connection with this very same L33ER with another L33ER in the plant. It works flawlessly! This confirms for me that the NATR module is not keeping this from working.

There is something going on between the L71 and L33ER that isn't an issue between 2 Compact Processors.

Thanks

Have you looked at the compactability matrix on ab website? Maybe see if there is a firmware problem with your revision?

It seems to be a problem with your rpi setting being too aggressive. Maybe back off the RPI to like 200 msec

Is this same brand of switches you usually use or different? Maybe there is some AB setting that is not set correctly on the switch?

Have you looked at the % utilization on your ethernet connection?
Go to any web browser, type in the IP, look at the module diagnostics. The % utilization during peak times should be below %50, if above maybe the RPI is too low.

Jim3846 said:

Have you looked at the compactability matrix on ab website? Maybe see if there is a firmware problem with your revision?

It seems to be a problem with your rpi setting being too aggressive. Maybe back off the RPI to like 200 msec

Is this same brand of switches you usually use or different? Maybe there is some AB setting that is not set correctly on the switch?

Have you looked at the % utilization on your ethernet connection?
Go to any web browser, type in the IP, look at the module diagnostics. The % utilization during peak times should be below %50, if above maybe the RPI is too low.

Click to expand...

Thank you for ht suggestions.
Using your advice, I did have a look at the Compatibility Matrix. The only red flags seem to be dealing with drives and the lack of an event task in the L33ER. I see no mention of anything that should prevent this from working a bit better.

Also, looking at the Web pages:
The L33 ER shows the I/O Comms Utilization at 13.2%. I also have other PLCs as well as 12 525 VFD s talking to this processor.

The L71 web Page shows lots of things but I do not see anything like the %Comms Utilization seen on the L33 WebPage. It does show the % CPU utilization peaking at 7.5%, not that I think it means anything here though. One other thing to mention. The connection between the 2 processors makes itself visible on the I/O Connections page of the L71 Web Page (1756-ENBT) when the connection is healthy, then it goes away.



I do notice, on both processors web pages, the amount of active connections going up and down by one every few seconds.


As far as switches. All the processors here are on small, local, un-managed switches that connect the machine LAN to the PLC Network, always using a NATR or an ENBT dedicated to the plant LAN. The plant LAN is over 2 large IT managed switches in which they have pre-tagged for me so many Industrial ports in each switch. They are Cisco. Really never have caused me an issue but if I have to Ill have to get IT involved..

I'm hoping that making the RPI settings greater will help. I can only work at (download) it between 5 and 7 AM though, so Ill be back at it tomorrow again.

Thanks for watching!

I'd suspect one of two thing:

• One of the controllers is running out of connections.
• Is is possible that there are 2 consumers out there trying to connect to the same produced tag?

Edit: KB QA469 says your error message (16#031e) does mean that another PLC is already consuming that tag.

Look on the controller properties and there is a connection display on capacity tab. Look at your ethernet nodes that DMroeder pointed out to you. I know its on the CompactLogix for sure, not sure if its on the L71, but thought the L71 had 120 connections. But your Ethernet card is another area to look also on the browser too. You can look at connections available, the older ethernet ENBT example has a lower packet size and lower connection count. Also check your Produce tag connection to see how many your Max consumers are set to on your produced tag. I thought IO config tree gave you info on your connections, so check there and on the browser interface.

The produced tag itself has a setting for "maximum number of consumers". If that's set to 1, then whichever consumer connects first will get it and lock the rest out, with the error you describe.

Have a look at the setup for the produced tag, you'll likely need to do a download to change it.

Only 1 Consumer folks!

I just put both of these processors on the network myself.

The L33ER does have 2 other Connections to other L33ER processors, 2 of them. And 12 525 VFD + 1 PV... The manual says I can have 32 connections.

The L71 Is in an OEM packaging machine. It has another ENBT module that has several other VFD and servo motors on it, but no other connections to the plant network ENBT that I put in for just this purpose. The manual says I can have 128 connections to this controller, I'm at no more than 20 currently.

Just to rule out the possibility of a freak consumer grabbing the tag as well, such as suggested by the fault codes description. I increased the max number of consumers on the Produced tag to 2. No change!



I cam in this AM to work on it. Supposed to be down from 5AM to 7AM. Its now 5:18 and they are still running..

Well It didn't' happen today. The downtime between night shift and day shift was to narrow... about 15 minutes narrow.
Its not critical so I'm not messing with their world this AM.

I really want to bump the RPI up on that produced tag and see if it helps.

Thanks for all the suggestions!

PLC Pie Guy said:

Well It didn't' happen today. The downtime between night shift and day shift was to narrow... about 15 minutes narrow.
Its not critical so I'm not messing with their world this AM.

I really want to bump the RPI up on that produced tag and see if it helps.

Thanks for all the suggestions!

Click to expand...

Found a KB article that says you should upgrade your ENBT firmware to 6.006.

dmroeder said:

Found a KB article that says you should upgrade your ENBT firmware to 6.006.

Click to expand...

Will do. Thank you.

Firmware it was!
First I tried setting the RPI up to 200ms as suggested, no change.
I then flashed it to V6.006 and the connection seems to be solid now.

Thank you for all the assistance.

Old thread but confirming the same issue with an L33ER v28 CompactLogix and L72 Communicating through a 1756-ENBT, v3.1. Upgrading firmware to v6.6 resolved the communication errors.