Quantum PLC Heartbeat Loss

Good Day,

We are stuck in a serious issue, please see below for details and give your valuable feedback.

- There are two PLCs running on site one is M340 and other is Quantum PLC.
- Both PLCs are sharing data with each other on ENET link and both have remote IO racks which are installed recently.
- Now we are having issue on Quantum side, the Quantum PLC stops and its heartbeat becomes zero after 22 to 24 hours.
- Then a reset of Quantum PLC resolves the issue and bring the PLC in function.
- All IO racks and modules installed n these racks are working fine, field to card communication is fine.
- Before the addition of remote IO racks, the communication was fine. We haven't came across this problem before.
- But after the addition the PLC was fine for 2 to 3 days.

Please help and share your valuable suggestions in this regard.


Regards,
Jawad Rasool

Is your heartbeat software generated or are you using system bits ? What happens when you connect to the Quantum and go on-line, is the program running, is there any fault codes generated ?

Have you upgraded all Ethernet cards to latest firmware revision, we have had issues with M340 sockets opening and not closing saturating the TCP channel. If you using I/O scanning, you need to be careful with your repetitive rate scan as if this is too short it can also have the same effect

tragically1969 what version of M340 OS did you have issues with half open sockets accumulating, and what was your application doing that caused that? Just IO scanning? I have one NOE0100 IO scanning 3 PLCs at 10ms rate step and another 10 devices at 300 ms.

jawad rasool, have you contacted schneider support? They have recently replaced Quantum CPUs for me on warranty that needed firmware or OS upgrades due to crashing/stopping with error EC02 and EC0E.

I can't remember the versions now without looking back, it was mainly related to READ_VAR out from the PLC and the slave failing to respond, it just basically stopped talking to anything, a reboot will fix it but the permanent fix was firmware.

We have had issues scanning large networks (30 PLC's) at small intervals, if you monitor the I/O scanning stats. you will see failures every now and again but that's just down to fine tuning.

I would put money on a firmware upgrade sorting it, trouble is upgrading firmware on Quantum's is tricky and they can easily be bricked, which is why we handed them to the Schneider tech guy to do the last time he visited us !

>>related to READ_VAR out from the PLC and the slave ... it just basically stopped talking to anything

This is a known issue. Something to do with the way the CPU talks to the Ethernet module (even the CoPro is a separate module) - they referred to it as backplane connections. I have dealt with this, and spent several weeks in Europe dealing with a customer who ran into the issue. Very annoying. They blamed it on our code - it's their programming tool, their device, it let us compile no problem... so I asked for a reference implementation - you know, 'yes, I screwed it up, so show me how to do it' - and all I got was crickets. I even provided Rockwell's excellent documentation on explicit messaging blocks... thought that would shame them into dealing with the mess that their blocks are, relative to competitors. Well, me against a 25+Billion Euro company - you can guess who lost.

Customer refused IOScanner because he could not change IOScanner on the fly, while read_var and the like could be changed while running. Only option then was to reset the module (pull away from backplane and push back in - any one who has dealt with Quantum must know this) when the issue occurred.

the same PLC I replaced the CPU on in post #3 has **** itself with an EC02 again this time on the new CPU with OS version 3.2. The OS version changelog indicates 3.4 fixes some conditions which cause EC02 and version 3.53 is the latest.



Of course Quantum is End Of Life now I think because of cybersecurity - they just can't be fixed or that is the excuse to push people towards M580 as M340 is hopeless for cybersecurity too.