User Manual

Logical I/O blocks
General functions
19
CM110664en_07 241 | 351
Prio Meaning Use Access via
5
immediately to the [PrVal] output. It is
not subject to the delay times defined
for priority 6.
Higher-level monitoring of critical plant
states:
- Frost in ventilation system (close
dampers, stop fans, switch pump on and
open valve)
BACnet command system.
Access via the CMD_CTL block.
6 Minimum switch-on/off time
Prevent unnecessary switching operations.
Switch-on/off delay
Can be used to ensure that run-on delay times are implemented.
No access!
Commands are only generated internally
in the block.
The timer periods [TiOnMin],
[TiOffMin], [DlyOn] and [DlyOff] can be
configured in blocks BO, MO, BVAL and
MVAL.
7 Operating value
Reserved for manual operation.
Local manual operation, e.g.:
- Manual switch
- Mode selector switch
Data flow interconnection via pins:
[ValSwi] und [EnSwi].
8 Higher-level manual operation, e.g.:
- Desigo CC
- Operating unit
- Web client
BACnet command system. Access via:
- Desigo CC
- Operating unit
- Web client
9...13 Not used in Desigo.
14 Program value
Reserved for normal plant operation
with monitoring and control.
Superposed control and monitoring of
the plant.
BACnet command system. Access is via
blocks:
- CMD_CTL
- PWR_CTL (if control enable signal =
Fixed)
15 Local control of plant. Data flow interconnection via pins:
[ValPgm] and [EnPgm].
If the program value is a controller
variable, then [EnPgm] = True and
[ValPgm] = controller variable.
If the program value is not a controller
variable, then [EnPgm] = False.
16 Program value
Reserved for general cross-PX
commands via BACnet references.
BACnet command system. Access via
blocks:
CMD_CTL
PWR_CTL (if control enable signal is =
Released)
Cross-PX via various blocks, e.g.,
ASCHED, BSCHED, MSCHED (name
reference list).
17 Default value [DefVal]
If none of priorities 1…16 is active, then
the default value [DefVal] is processed
instead.
The influence of [DefVal] depends on
the state of the block concerned:
Out-of-service [OoServ=False]:
[DefVal], like the values of priorities
7…16, is subject to the delay times of
priority 6.
[OoServ=True]:
[DefVal] is transmitted immediately to
the [PrVal] output.
BACnet command system. Access via:
- CFC
- PXM20
- Web client
Example: Effect of priorities 7...16 on [PrVal]