Device Recovery
- Last UpdatedMar 08, 2024
- 1 minute read
Device recovery refers to the process that occurs when a device goes offline (due to interrupted communication) or the system is starting.
There are two modes to recover a device:
The first two attempts to recover a device will place the integrity/static polls with high priority in the DNP3 transmission queue. This means that these polls will be transmitted before any other requests in the exception of write time, delay measurement and control requests. If the device is still not recovered after the first two attempts, then the priority of the subsequent integrity/static polls is the same as the periodic polls of online device. This is to give the change to online device to be polled.
Once a device is recovered then the periodic polls will be staggered if the Citect.ini parameter "[<unit>] PollPeriodOffset" is set.
The Citect.ini parameter to enable one or the other mode (integrity/static polls) is called "[DNPR]IssueIntegrityPollOnUnitRecovery" or "[<unit>] IssueIntegrityPollOnUnitRecovery". If set to 0 (default) then static polls are issued otherwise integrity polls are issued.
It is also possible to issue Class 1, Class 2, or Class 3 poll on the device recovery. You can enable this behaviour by the Citect.ini parameter "[DNPR] IssueClassPollOnUnitRecovery" or "[<unit>] IssueClassPollOnUnitRecovery". By default, these parameters remain in disable mode. So the unit will recover based on the "IssueIntegrityPollOnUnitRecovery" ini parameter.