I have one Central Safety System (H51Q-HS) and 5 RTU's (H41Q-HS) defined on a project. All HIPRO/S communication is fine except that safety variables on 2 out of 5 RTU's are toggling (1 for a few seconds and 0 for another few seconds, then back to 1).

I have checked and removed all errors/comments in PES Docu but cannot seem to resolve this problem. Currently these safety vars are forced and the plant is running fine but the client won't tolerate this for long. Any suggestions?

 

Sounds like there is a problem with the communications link or the application code. If there is an intermittent comms drop out the HIPRO-S data will be set to the safe state. You can modify this time value within ELOPII but DO NOT exceed 50% of your safety time!