User Manual

Logical I/O blocks
Output blocks
19
258 | 351 CM110664en_07
OPEN end switch -> Feedback polarity [FbPol] set to NORMAL
CLOSED end switch -> Feedback polarity [FbPol] set to INVERTED
Feedback monitoring for dampers with two end switches
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)
● Reliability monitoring [Rlb] (FAULT alarm)
● Change of state messages (events / system events)
● Configurable switch type (Normal, Motor, Trigger)
● Runtimes and monitoring periods
● Hardware mapping (refer to Section 0)
● Runtime totalization and maintenance messages
● Process monitoring [StaFlg]