User Manual

Control concept
Control concept and control blocks
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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.
Status monitoring
[AO, BO, MO, AVAL, BVAL, MVAL]
The process is monitored via the feedback signal, and in the case of switching
blocks, also via the ramp-up and ramp-down parameters set in [TbTiDly]. If the
feedback value deviates from the present value [PrVal] and the delay in
[TbTiDly] has not yet expired, the process is in a transitional state. The status
monitoring function shows the status at the transient state [TraSta] output.
This output can be used to switch on any subsequent components.
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