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Siemens
TX-I/O™ Module system – Functions and operation
CM110561en_08
Building Technologies
Indicators and operator controls
2018-10-25
2.2.2 I/O status LEDs
•
The status LEDs for individual I/O points (green or three colors
1)
) are situated on
the plug-in I/O module.
They show the status of the input or output.
•
The LEDs are labeled with the I/O point number.
•
The display
depends on the type of input/output signal:
Description
LED (green)
1)
Field devices
Normal
OFF
N/O or N/C contact inactive, relay inactive
ON
N/O or N/C contact active, relay active
Brightness varies in proportion to
input value
Analog input
(current, voltage, temperature, resistance)
No display
Analog input
(temperature; P-bus BIM: also resistance)
Brightness varies in proportion to
output value
Analog output
(current, voltage)
Reminders / Errors
Several flashing patterns
For details about errors please refer to the section
"Indication, operation, and diagnostics" in the
TX-I/O™ Engineering and installation guide [6].
1)
On certain module types the LEDs are three-color. If the I/O function supports it, the
LED can display Alarm = Red and Service = Yellow, in addition to Normal = Green
(default).
2.2.3 LCD display
The following information is displayed for each I/O function:
– Signal type (lower part of display)
– Signal value (process value)
(graphics-supported display of pulse or analog value)
– Faults (incorrect operation, short-circuit, open sensor circuit, etc.)
Examples
?
V A Ni
1056
1D
206
For details please refer to the section "Indication, operation, and diagnostics" in the
TX-I/O™ Engineering and installation guide [6].
Example: digital input
Signal type
Contact I/O status LED
LCD
Process value
D20
N/O contact
Open
Closed
OFF
ON ("N/O contact active")
0
1
D20R *)
N/C contact
Open
Closed
ON
OFF ("N/C contact active")
0
1
*) If D20R is not supported: use D20 with
Polarity = Inverse.