Operating Instructions

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Siemens TX-I/O™ Module system – Functions and operation CM110561en_08
Building Technologies Digital input functions 2018-10-25
3 Digital input functions
The following functions for digital inputs are available in the TX-IO™ range:
Description
Signal type (TRA)
Signal type
Status indication, maintained contact N/O or N/C
BI NO
BI NC
D20
Status indication, maintained contact N/C
(P-Bus-BIM only)
-- D20R
Status indication, pulse contact N/O
BI Pulse NO
D20S
Pushbutton input single / dual
BI Push NO
BI Push NC
--
Counting, pulse contact N/O
CI Mech (10/25Hz)
CI El (100Hz)
C
Multistate input
MI Switch
--
3.1 Status indication, maintained contact
(BI NO, BI NC / D20, D20R)
Acquisition of status signals from volt-free contacts and electronic switching devices
such as transistors and optocouplers.
The status signals can be triggered by
– Two-position transmitters such as thermostats and pressure switches etc.
– Status contacts of devices and auxiliary contacts of starters / switches
– Electronic switching devices such as transistors and optocouplers
– Pushbuttons
The function requires one I/O point.
LCD
Process value
I/O status LED
N/O Contact
BUS
10561Z154_01
Normal
Service
Alarm
LCD
Process value
I/O status LED
N/O, N/C Contact
BUS
Normal
Service
Alarm
Signal Processing (D20, D20R)
1
N/O
N/C
Island bus
Integration
via P-Bus
BIM
Block diagram of function
I/O functions
Application
Hardware
Function