Applies To:
  • CitectSCADA 1.00 1.01 1.10 1.11 1.20 2.00 2.01

If you have a Primary and Standby unit and you wish to get the status using UnitInfo() you will get the primary unit status as the default. 

You may specify the standby unit directly by adding ",s" to the end of the unit name when you call the UnitInfo() function. You may also specify the primary unit directly by adding ",p" to the end of the unit name. For example if you have a primary standby configuration for a unit called UNIT1 you may access each unit as follows:

UnitInfo("Unit1,s", 10); ! get standby
UnitInfo("Unit1,p", 10); ! get primary

You may also get the status of individual units by changing the name of the Standby units. In the Units database there is a Unit Number and a Unit Name. The Unit name is used by the compiler so that it can find the protocol of the unit. The unit number is used at runtime as it is more efficient than using a name. If you change the name on the Standby, the compiler will find the name it expects on the primary unit. The Unit numbers must remain the same for the redundancy to work. By changing the name on the Standby so that it has a different name to the primary, you can use the different unit name of the Standby to find the status.

For example:

Unit Name Unit Number Startup Mode

UnitInfo("Unit1S", 10); ! get IO Server State for the standby unit.
UnitInfo("Unit1P", 10); ! get IO Server State for the primary unit.