Applies To:
  • CitectSCADA
  • CitectHMI
Summary:
What does "Server Status: Stopping" mean on the Page Unit Statistics in the Kernel?
 

Solution:
The server status section on the Unit Statistics page in the kernel indicates the status of the IO device. The status can be PRIMARY, STANDBY, STANDBYWRITE, OFFLINE and STOPPING. "STOPPING" means the unit is shutting down.

There are three reasons why this status would be set:

1. When drivers are shutting down, Citect loops through all the units and sends a CTDRV_STOP_UNIT command to the driver. Just before this, it sets the unit status to UNIT_STOPPING, so that the stats in the kernel will reflect that the STOP_UNIT command has been sent to the driver. Citect then waits for a reponse from the driver up to a timeout (1 second) and sets the unit status to UNIT_OFFLINE.

2. The server status of a dial up IODevice will be shown as "STOPPING" when Citect is shut down.

3. When a unit is disabled.

There is also an INI parameter that affects the stopping of units:

[IOSERVER]AlwaysCallStopUnit

This is documented in the help.
 
Keywords:
stopping, server status, kernel  

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