I am running DeltaV version 7.4, we lost power to the controller for approx 2 minutes and when the system was restarted there was an error. The error stated that there was no Configuration in the controller.
I downloaded the configuration to the controller and we were back online within a few minutes.
My question is, should the controller not hold the configuration?
Check "Controller Cold Restart time"
In reply to Roman Kostuniak:
Hello Louise,
In Version 7 there are 2 situations that can prevent a controller from automatically recovering from a power failure. First, as Roman pointed out you must explicitly provide a configuration setting for the "Cold restart perform within" controller property (this is the worst-named property in DeltaV I think). View the controller properties in DeltaV Explorer to find this. The default value is "0" which means the controller will NEVER automatically recover. As long as the power failure duration doesn't exceed the time you define here, the controller will use its stored copy of the configuration in nonvolatile ram ("cold restart memory") to automatically recover from a power failure. We typically set ours to 23 hours.
BUT WAIT THERE IS MORE! The controller will not reboot from cold restart memory that has been invalidated. The controller's cold restart memory can be easily invalidated if someone had previously Uploaded changed parameters from the controller, and did not immediately download controller cold restart memory. Starting in Version 9 this cold restart memory download is done automatically in the background but in Version 7 you must perform this step manually!
You can determine whether the controller will automatically recover from power failure by viewing the controller in DeltaV Diagnostics, specifically the property called "cold restart source". If the value for "cold restart source" is WORKSTATION then cold restart memory is invalid and the controller WILL NOT AUTOMATICALLY RECOVER and will require a manual download following a power failure. If the "cold restart source" is CONTROLLER then the controller WILL automatically recover from power failure.
At our facility we configured a single display in DeltaV Operate that shows important controller diagnostic properties including Cold Restart Source from all of our controllers, right in one place (easier to see at-a-glance than clicking all over the place in Diagnostics), so that before we go home we can glance at the display to make sure controllers could recover if a power failure occurred overnight.
The "cold restart" recovery process takes 2 or 3 minutes to complete once power is restored.
In reply to Pat Grider:
Pat is not entirely correct. When the restart location is Workstation the controller requests the restart download from the Pro Plus. The controller should still be automatically be reconfigured.
If Cold restart was enabled, the controller event log should be checked for a restart event. If the log does not show a power fail event, the power outage time stamp will not be captured and the restart time is calculated from 1978 So obviously the restart time is expired.
If the restart is enabled, but did not execute, you should log this withe GSC. They can cross reference your specific software version with known issues.
Andre Dicaire
In reply to Andre Dicaire:
Hey Andre,
Not to put too fine a point on things, it's safe to say that if the restart source is Controller then there is maximum chance for automatic recovery from power-cycle because all required elements are available to the controller without depending on a functioning network or availability of the ProPlus.
Yes that is correct. On a power outage, many controllers may be affected. Controller locaotion for restart willl also speed recovery. It is recoMmended to have restart location in controller.