AnalogDevice object state changes

Startup

None.

Going onscan

• If the PV.Mode is set to Manual, then the PV is the last value, and the quality is UNCERTAIN.

• If the PV.Mode is set to Auto, then the PV is the Not-a-Number (NaN) value, and the quality is INITIALIZING. The NaN value is defined by the Institute of Electrical and Electronics Engineers, Inc. (IEEE).

• PV.Auto is set to NaN value, and the quality is INITIALIZING.

• If the object is an analog regulator, then the SP is the NaN value, and the quality is INITIALIZING.

• Any pending deviation alarm timer is reset.

• The time stamp of PV is set to the current time if the NaN value and INITIALIZING quality is set to PV. The time stamp stays unchanged if the value stays at the last value and no quality change.

Onscan

The object is active. For more information, see AnalogDevice object continuous execution: general, AnalogDevice object continuous execution: PV alarms, and About the continuous execution: scaling equation.

Going offscan

• If the PV.Mode is set to Manual, then the PV is the last value, and the quality is UNCERTAIN.

• If the PV.Mode is set to Auto, then the PV is the NaN value, and the quality is BAD.

• If the object is an analog regulator, then the SP is the NaN value, and the quality is BAD.

• All alarm conditions become false and input values go to BAD quality.

• Any pending deviation alarm timer is reset.

• The time stamp of PV is set to the current time if the NaN value is set to PV, PVAuto, or SP. If the PV.Mode is set to Manual, then the time stamp stays unchanged if the value stays at the last value and quality is UNCERTAIN.

Offscan

The object is passive.

Shutdown

If references to the PV and/or SP attributes were registered and suspended at startup, these references are activated and unregistered.