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Posted: 2025-09-17 04:53 PM
We are currently working on a system upgrade project where we have migrated from a Quantum PLC (communicating with ETG100 via IO Scanning) to an M580 PLC communicating with PAS600L.
In the previous setup, IO Scanning functioned reliably and consistently. However, after the migration, IO Scanning was replaced with DTM communication. We have configured the M580 PLC to communicate with PAS600L using the DTM, but we are encountering a critical issue:
We would appreciate your guidance on the following points:
We would be grateful for any documentation, configuration examples, or troubleshooting steps you can provide to help resolve this issue.
Thank you for your support.
Best regards,
Krishnakumar Ramasubbu
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Posted: 2025-09-29 10:15 AM
hello, verify that the time out of the serial bus on the PAS600 (configuration PAS600 with web page) is lower than the time out of the DTM request, and select Gateway\bridge device on the DTM
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Posted: 2025-09-18 12:35 AM
Hello @Sesa460428 ,
ETG100 was an old gateway => No more support (including Modbus stack). If you still use this gateway, you may encounter some communication issue if the Modbus stack is overloaded.
Regards Panel Server, I'm not aware of any issue regarding Modbus polling.
Now, we need to understand your architecture and how PAS600 is used as a gateway:
I do not think the M580 can "stress" the Panel Server to block the Modbus stack. I will let the PLC experts answer regarding the DTM.
Regards,
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Posted: 2025-09-18 01:19 AM
Hi Romain,
Thank you for your prompt response!
Please find attached the existing MV System Architecture. We are currently in the process of replacing the Quantum PLC and ETG-100 with the M580 PLC and PAS600L.
In the field, we have SEPAM Series 80 devices connected via ACE949-2. For your reference, I’ve also attached screenshots from the DTM query.
Each SEPAM is configured to read from addresses 464001 and 403217, and we are writing to 3208.
Please let me know if you need any further details or clarification.
Best regards,
Krishnakumar Ramasubbu
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Posted: 2025-09-18 08:48 AM
hello,
you are using a PAS600 as a gateway, so try to tick "gateway" for all requests.BR
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Posted: 2025-09-28 12:21 AM . Last Modified: 2025-09-28 12:24 AM
Thank you for your prompt response.
We are still facing issues in our setup where PAS600L is communicating with four SEPAM devices. Specifically, we’ve observed the following:
When one or more SEPAM devices lose communication, the values from other devices intermittently drop.
The freshness indicator for those values also becomes zero, even for devices that are still online.
While PLC switchover communication lost and all Input values getting zero and then it is taking time to re-establish the communication.
This behavior is affecting data reliability. Has anyone encountered similar issues or found a workaround to maintain stable data flow and freshness when partial communication loss occurs?, If you could share working backup it will be very useful for us.
Any insights or suggestions would be greatly appreciated.
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Posted: 2025-09-29 12:20 AM
Hello @Sesa460428 ,
I can only help for Panel Server.
I suggest to contact our tech support to faster the resolution.
Did you check if communication is OK on PAS600 side ? In case of communication loss of 1 sepam, can you still reach the other ones directly from the Panel Server web page (Read Register feature). Or with a basic Modbus Client upstream the PAS600 ?
Regards,
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Posted: 2025-09-29 10:15 AM
hello, verify that the time out of the serial bus on the PAS600 (configuration PAS600 with web page) is lower than the time out of the DTM request, and select Gateway\bridge device on the DTM
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Posted: 2025-10-03 07:21 AM
"Thank you. Communication is now established between SEPAM and PLC, although there are some device failures. However, during PLC switchover, the values are resetting to zero. We are transferring data from the DTM to the memory location only when the freshness flag is set to one." Would you like me to help you troubleshoot the zero values during switchover? For example: Should the memory retain the last known value during switchover? Is the freshness flag being reset or delayed during the transition?
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