IAC between 2 controller HI 865 by microwave for application SIL3
Dear all,
We use IAC to communicate between 2 controller HI 865 by microwave. But the microwave is not stable, signal sometimes loss and I see one controller shutdown.
Please help us how to improve this case that means we don't want controller shutdown due to loss communication.
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Answers
Hello,
I hope you have taken care of the all AC 800M HI Safey Manual recommendations while configuring IAC between PM865 controllers in SIL3 application(s).
The below are the snap shots from AC 800M HI Safety Manual.
If all above are ok and one controller is getting shuntdown due to failure of IAC communication (ISP values on "IN" data direction variables are cuasing the shutdown)? If yes you may configure the ISP values accordingly without breaching safety integrity of respective SIF.
In IAC Communication are you using Alarm state transfer
i.e alarm condition state communication between controller
As the log in S02 (This controller sometimes shutdowns without rootcause):
Post Mortem controller log:
I 2016-06-08 02:10:54.321 ... flushed 3 messages (first message might be repeated)
I 2016-06-08 02:10:52.853 Scan_Task primary SM (1) restarted due to two CRC errors on outgoing telegrams
E 2016-06-08 02:10:52.949 ErrorHandler PM: 4180 MBM1 SM vs PM CRC32 fail ad 0x13 (1,2)
E 2016-06-08 02:10:52.951 ErrorHandler PM: 4180 MBM1 SM vs PM CRC32 fail ad 0x93 (1,3,ERS)
I 1979-12-31 00:00:00.000 Flushing modulebus frame discrepancy buffer:
E 1979-12-31 00:00:00.000 Modulebus frame discrepancy
Adress AccessType Ch16 (bin) Ch1 Unused To Fr Mi Ma Ci
PM: 103 WriteDigital 0000000000000000 00000000 13 00 00 0A 13
SM: 103 WriteDigital 0000000000011000 00000000 13 00 00 0A 13
Adress AccessType Ch16 (bin) Ch1 Unused To Fr Mi Ma Ci
PM: 903 WriteDigital 0000000000000000 00000000 93 00 00 0A 13
SM: 903 WriteDigital 0000000000011000 00000000 93 00 00 0A 13
Adress AccessType Ch16 (bin) Ch1 Unused To Fr Mi Ma Ci
PM: 103 WriteDigital 0000000000000000 00000000 13 00 00 0A 13
SM: 103 WriteDigital 0000000000011000 00000000 13 00 00 0A 13
This PM has been automatically restarted.
Reason:
- Manual shutdown was requested (Acknowledged)
So I think something was wrong that make channel 4 & 5 discrepancy between PM & SM
Please see logic and communication variable between S01 and S02. Note: S01 never shutdown but S02 sometimes.

From the screen shot:
SO2 having IAC in variable , but why are use the softcontroller IP !74.16.X.X:10 in the ip address of IAC
One more thing. When FAT they program 3 SCM: xHZ_4507A_OGT, xHZ_4508A_OGT, xHZ_4509A_OGT
3 theses SCM connect to parameter gIO with data type dtIO.
Normally gIO will connect "hardware variable" but after commissioning they delete these variables in hardware. So just remain 3 variable in data type: "BoolIO"
So I think SCM "MB_DigitalInType" of librabry Reuse with SIL3 need actual digital input.
Maybe this rootcause make S02 sometimes shutdown due to violate SIL3???
Hi,
As mentioned before, it could be something else than the IAC. I have no experience with IAC but looking at the controller log I have some suggestions you can check.
As it looks from the controller log there is an error between the PM865 and the SM810/SM811 regarding the information from the module bus.
-Check the module bus error counters.
-Check also the CI log which can contain logging from the SM module.
-Check modulebus scan time versus the task schedule and controller load.
-It could be a hardware failure on one of your cluster modems 1 or 9.
-It could be a hardware failure of the cabling between the redundant PM or SM.
-I noticed the timestamp E 2016-06-08 02:10:52.949 indicating this error occured more than a year ago. How are the PM's time synchronized?
Regards.
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