AO/BO feedback
The alarm extensions provide feedback in points to prevent the detection of alarm conditions that are really false alarms. For the analog alarm extension, this feedback is done through the configuration of the Setpoint Reference attribute. For the multistate alarm extension, this feedback is done through the configuration of the Command Reference attribute. When you reference other attributes using the Setpoint Reference or Command Reference attributes, the alarm analysis works differently.
Analog Points:
For example, add an analog alarm extension to an Analog Input Object (zone temperature). Define the Present Value of the Analog Input Object as the Input Reference and define the Define the Present Value of an Analog Output Object (setpoint) as the Setpoint Reference of the analog alarm extension.
If you edit the Setpoint (Define the Present Value attribute of the Analog Output Object), the Warning Reference attribute of the analog alarm extension of the Zone Temperature Analog Input Object changes to the same value. The Reference Delay Time of the analog alarm extension resets at this same time and prevents a false alarm condition from being detected.
Binary or Multistate Points:
For example, add a multistate alarm extension to a Binary Input Object or Multistate Input Object. Define the Present Value of a Binary Input (fan status) or Multistate Input as the Input Reference; then define the Present Value of a Binary Output Object (command state) or Multistate Output Object as the Command Reference of the multistate alarm extension.
If you edit the Command State (Present Value attribute of the Binary Output Object or Multistate Output Object), the Normal State attribute of the multistate alarm extension of the Fan Status Binary Input Object or Multistate Input Object changes to the same value. The Reference Delay Time of the multistate alarm extension resets at this same time, preventing a false alarm condition from being detected.