User Manual

Control concept
Control concept and control blocks
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CM110664en_07 69 | 351
Level Application Description
Safety level Life safety The safety level is assigned the highest priority and is used for the protection
of people and equipment. This is where local safety switches and emergency
OFF buttons are wired or superimposed commanded, e.g., smoke extraction
control or frost control.
Plant safety
Operator level Local manual intervention The operator level is where components are overridden manually. Here the
operator unit may be used to force the output of an I/O function block. This
operation overrides all operations at a lower priority level.
Superposed manual
intervention
Automatic level Local control The automatic level is used for local control functions and for superposed
BACnet commanding.
General BACnet
commanding
The following figure illustrates the structure of [PrioArr] and the influence of local and higher-level control.
Local override
The override switch overrides the block's switching value and determines in this way the switching value
for the field device. Local override has priority over an active manual operation at the same time, that is,
priority over local override.
2
5
8
14
16
15
13
9
7
6
3
1
PWR_CTL
CMD_CTL
ValPgm / EnPgm
PrVal
ValCrit / EnCrit
Desigo CC
ValOp / EnOp
BOAO MVAL
e.g. local manual
switch
Local control
e.g. anti-icing
protection
e.g. emergency stop
Priorities 1, 4, 7, 15
via data flow interconnection
Local control
General BACnet command
Life safety
Critical value
Monitoring hours
Manual operation
Program control
Priority 6
Control within block
Priorities 2, 5, 8, 14, 16
via BACnet command
Higher control