CompactLogix 1769 l35e ethernet hanging up?

kf5pv

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Join Date
Aug 2008
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Fort Worth
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Has anyone else seen or heard of this?

I have about 27 connections but seems my message statements are hanging up at times.
(usually around 45 to 70 seconds.) I think also when this happens I get booted offline.
I am going through a NAT module but doing all of my reads and writes out of that processor.
I have tried 10 different ways to schedule the different messages. going to replace the processor just to see but not until tomorrow?
Hate having to set my watchdog timers to 100000.
Among some other issues it is causing.

Thanks in advance

Paul
 
Maybe you have too much traffic on the network causing the messages to time out or the packets are getting dropped.

Need more info about your network, speeds, what kind of switches, etc.
 
Havent really looked into the network issue because I am not getting any errors on the MSG statements.
Its almost lile the processor just haults or stops scanning.
I think we evan put some counters in to see if we could capture any errors on the MSG.
Its in my main ladder with some JSR's before them but I dont think that should matter.
when it is running the time it takes to execute is about 10ms max. from enable to done.
 
I had ip issues on a l35e a while ago, and tech support pointed me first up to the plc ip module web interface.. It has a bunch of performance / error information which may point out where your problem is ??
 
I really didn't think there was anything you could do with communications that would freeze the processor. To the contrary, communications get sacrificed if logic needs to run. If you are getting scan times that require a 100 second watchdog it would seem something is causing your program to run in circles.

Keith
 
actually I havent looked at scan time yet.
The 100 seconds is in the watchdog of the processor I am writing to.
Had same issue with other types of processors also being read and wrote to from the L35E.
I will go look at the web interface shortly.

Thanks
 
Checkbox Autonegotiate speed

We had intermittent total PLC Ethernet lock up also.
When using the Ethernet diagnostics counters under the properties tab, we would see errors continuously ratcheting up. There turned out to be about (6) of (20) Ethernet/IP devices in the PLC I/O scan that were limited to 10mbps.

After a power cycle to the PLC, it could run for one to two days and then freeze ALL Ethernet communications.

Once we checked Auto-negotiate speed, there were zero errors, and the problem gone.
 
Auto negotiate checked.
I am however having an issue with the plc ip module web interface described above. it is giving me a mis-match on the module.
I will look further at that as time permits.
 
have you flashed the processor recently ?? There is a warning that pops up before you start with an IP processor advising bad things can happen if the flash gets interrupted around the IP interface...

Seems worth trying to flash and see :)
 
Nat

I assume your PLC is on the LOCAL port of the NAT.

Make sure that you PLC configured GATEWAY IP address is set to the LOCAL Port NAT IP address
 
We had intermittent total PLC Ethernet lock up also.
When using the Ethernet diagnostics counters under the properties tab, we would see errors continuously ratcheting up. There turned out to be about (6) of (20) Ethernet/IP devices in the PLC I/O scan that were limited to 10mbps.

After a power cycle to the PLC, it could run for one to two days and then freeze ALL Ethernet communications.

Once we checked Auto-negotiate speed, there were zero errors, and the problem gone.

This sounds VERY similar to issues I'm having with SLC-5/05 to ControlLogix Messaging. SLC-SLC works just fine.

I have Series B SLC-5/05s in this system - which can only run at 10Mbps@Half Duplex. The firmware, however, flashed to Series C. I set all of the SLC-5/05s for Auto Negotiation (as reccomended by Rockwell -even though it doesn't change the speed), and replaced the networking switches with modern Cisco switches - also set for AutoNegotiation.

I'm still having issues with the MSG instructions timing out. Any other thoughts/ideas?

The only difference is that the SLCs are all on a 10.10 network, and the ControlLogix are set on a 10.11 network - but with a /8 Subnet mask. The Messaging does work for some time - and then hangs up and continually errors out.
 
This sounds VERY similar to issues I'm having with SLC-5/05 to ControlLogix Messaging. SLC-SLC works just fine.

I have Series B SLC-5/05s in this system - which can only run at 10Mbps@Half Duplex. The firmware, however, flashed to Series C. I set all of the SLC-5/05s for Auto Negotiation (as reccomended by Rockwell -even though it doesn't change the speed), and replaced the networking switches with modern Cisco switches - also set for AutoNegotiation.

I'm still having issues with the MSG instructions timing out. Any other thoughts/ideas?

The only difference is that the SLCs are all on a 10.10 network, and the ControlLogix are set on a 10.11 network - but with a /8 Subnet mask. The Messaging does work for some time - and then hangs up and continually errors out.

I would adjust the IP addressing so you're not supernetting anything and check the way the firing of you message instructions is structured.

As a test try Setting the S:2/15 bit to 0 and see if it improves.
 
Moderator here: Please, let's not diverge and try to solve two different problems here. Open another thread, or link to an existing one, to discuss the SLC issues.

Let's stick to the CompactLogix that's "hanging up".
 

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