User Manual

Logical I/O blocks
Output blocks
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CM110664en_07 255 | 353
To monitor the damper position of dampers with one end switch, the switch
position must be set by defining the polarity of the feedback signal [Bop].
OPEN end switch -> Feedback polarity [FbPol] set to NORMAL
CLOSED end switch -> Feedback polarity [FbPol] set to INVERTED
The monitoring of dampers with two feedback signals (Open/Closed) is
implemented via the address string of the Feedback Address [FbAddr]. The first
address in the string must be that of the end switch which indicates that the
damper is closed. The end switch indicating that the damper is open is set in
the second part of the address string.
Example with PX modular:
P= M1.K1; M2.K2 (D20)
● 1. 1st address: Damper-CLOSED switch
● 2. 2nd address: Damper-OPEN switch
● Feedback polarity [FbPol] NORMAL
M1.K1 = True; M2.K2 = False -> Feedback value: Closed
M1.K1 = False; M2.K2 = True -> Feedback value: Open
When the damper is being driven to the OPEN or CLOSED position, this
transient state [TraSta] is displayed. If the preset monitoring time is exceeded,
an alarm is initiated. If the damper fails to reach an end position, the alarm is
reset again after the monitoring time has expired. There is otherwise no
automatic block reaction, that is, if a switch response in the plant is required as
a reaction to this alarm, this response must be programmed in CFC via the
disturbance output [Dstb].
Multistate Output (MO)
The multistate output is the logical memory map of a multi-state switching
command, and describes its properties. Within the program, the current value is
made available as a program value to the block and transmitted after
conversion into raw-data format to the physical I/Os. Here the raw data is
converted into a digital signal, e.g., which drives the field device via a contact. It
is also possible to connect a multistate feedback signal, which is used for alarm
evaluation.
The following functions are integrated in the block:
● Evaluation of the priority array [PrioArr]
● Interruption of the output signal [OoServ]
● Feedback monitoring (OFFNORMAL alarm)
Feedback monitoring
for dampers with one
end switch
Feedback monitoring
for dampers with two
end switches