Read-out error D-Word for A1 PLC

[Theo V 17]

Dear all, Last week I had an A1 PLC in error. I was wondering if there is a D-register that contents the error which caused the PLC to go down. Especially the D-register that keeps the information of previous errors because we had to power down the PLC to reset the problem. The problem did not happend again but i like to know how to deal with it when it does. I Know there are some D9000 registers to show internal errors like battery fail however I don't know if there is also a register that shows the last and second last error after power down. I hope someone has the answers to this. I'm looking forward to hear from you. Best regards, Theo V.

[Vasa 0]

Hey Theo, Did you check D9008 - "Self Diagnosis Error"? It stores the error data until you either reset it in the program or turn the key on the PLC to Reset position. -Vasa

[Gambit 326]

The A series is an old PLC which doesn't support retaining error information after a reset. You shoud switch the system to system Q which does retain the error data on PLC level but also on each special module

[Theo V 17]

Hi Vasa and Gambit, Thank you for the fast reply. @Vasa, Unfortunatly the error happend while I was not present at the location so the reset key is used and the power switched off and on by a collegue in an attempt to solve the problem so the information in D9008 is gone. The attempt worked out fine however I always want to know what was the reason of the CPU to go into error and try to solve and avoid this in the future. @Gambit, We are currently replacing all A1, A2 to Q-series and FX0/FX1 for FX3-series (no FX5 used yet) and Beijer E-Terminals to GOT touchpanels and we are at >60% of the equipment now worldwide but this is a long term proces (over 100 PLC's) so we have to keep the A-series alive for two or three more years. (it's all about the money...) I keep some of the old replaced parts as a spare as most of this is not available anymore. The Mitsubishi's have proven their reliability trough the years that's why we are replacing with the same brand and also convert the serial connections to industrial Ethernet to be ready for the future. Thanks again and best regards, Theo V.