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
3.2 Status indication, pulse contact
(BI Pulse NO / D20S)
(Function for P-bus BIM: See section 3.3)
Used for the acquisition of status pulses from volt-free pulse contacts and electronic
pulse transmitters such as transistors and optocouplers.
The pulses can be triggered by:
– Mains voltage monitoring systems
– Emergency pushbutton signals, e.g. in elevators
– Start-up monitoring for analysis of faults
• The function requires one I/O point
LCD
Signal Processing
(D20S)
Memory
Process
value
Acknowledge
I/O status LED
NO Contact
BUS
BUS
10561z156
Block diagram of function
• The signal is read and debounced on hardware level
• An additional debounce time is available: 0…25.5 s (default = 0 s)
• The pulse is then saved and transmitted to the bus master
• The bus master acknowledges receipt (Acknowledge)
• The memory is cleared, the LED goes off, and the input is ready for a new pulse
Additional incoming pulses before the Acknowledge are ignored.
• The signal operation can be selected: Contact_NO (default), Contact_NC)
Digital inputs cannot be overridden locally. The override button has no effect, and if an
attempt is made to operate it, an error is displayed.
• The I/O status LED does not show the source signal, but the state of the signal
memory
• The LCD panel (if available) shows the source signal type (status contact, N/O or
N/C contact)
• The LCD panel shows the change (a block of 3 fields which change with each pulse):
Application
Hardware
Function
Local override
Display