User Manual

Alarm management
Alarm response of the function blocks
9
CM110664en_07 145 | 353
Alarm response of the BACnet Device Object is also parameterized or depicted
by the number of variables, but the display differs: The BACnet Device Object is
not displayed by a D-MAP function block, but rather only visible via BACnet.
The variables described are therefore only accessible as properties of the
BACnet Device Object.
Binary Input and Binary Value
The alarm handling process is identical for the function blocks Binary Input and
Binary Value.
● An OFFNORMAL alarm occurs when [PrVal] assumes the value specified by
the variable [RefVal] for a time period at least equivalent to the delay time
specified in the variable [TiMonDvn], [TiMonOff] or [TiMonOn].
● An existing OFFNORMAL alarm condition will disappear (a) when [PrVal]
assumes the value complementary to [RefVal] for a period at least
equivalent to the period specified in [TiMonDvn], [TiMonOff] or [TiMonOn]
or (b) when [EnAlm] is changed from TRUE to FALSE (see further below).
● A FAULT alarm is generated when the [Rlb] property of the function block
assumes any value other than NO_FAULT_DETECTED. In particular, this is
the case when [Rlb] changes from a value not equal to
NO_FAULT_DETECTED to another value not equal to
NO_FAULT_DETECTED.
● A FAULT alarm will disappear as soon as the [Rlb] property of the function
block changes from a value not equal to NO_FAULT_DETECTED back to the
value NO_FAULT_DETECTED.
Binary Output
The alarm handling process in the binary output function block is essentially
different from that of the binary input and binary value blocks.
● An OFFNORMAL alarm occurs when the current values of the variables
[PrVal] and [FbVal] differ from each other for a time period at least
equivalent to the delay time specified in [TiMonDvn], [TiMonOff] or
[TiMonOn].
● An existing OFFNORMAL alarm will disappear when the current [PrVal] und
[FbVal] are again identical and remain so for a period at least equivalent to
the time specified in the variable [TiMonDvn].
● A FAULT alarm is generated when the [Rlb] property of the function block
assumes any value other than NO_FAULT_DETECTED. In particular, this is
the case when the [Rlb] property changes from a value not equal to
NO_FAULT_DETECTED to another value not equal to
NO_FAULT_DETECTED.