Operating Instructions
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Siemens TX-I/O™ Module system – Functions and operation CM110561en_08
Building Technologies Indicators and operator controls 2018-10-25
2.6 Fault messages
Quality value
Signal type
Normal
Invalid
No Out
put
(DC 24 V)
No Output
(AC 24 V)
Unreliable Other
Multistate Fault
Over Range
Under Range
Shorted Loop
Open Loop
No Sensor
Quality Value = part
of process value
BI NO / NC
x
x
BI Pulse NO / NC
x
x
BI Push NO / NC
x
x
CI Mech (10/25Hz), CI El (100Hz)
x
x
BO Relay NO / NC 250V
x
x
x
BO Triac NO / NC
x
x
x
BO Bistable NO / NC
x
x
x
x
BO Pulse On-Off
x
x
x
BO Pulse
x
x
x
MI Switch
x
x
x
MO Steps
x
x
x
x
MO Pulse
x
x
x
x
AI xxx
x
x
x
x
x
x
x
x
AO 0-10V, AO 4-20mA
x
x
x
x
x
BO 3-Pos Relay
x
x
x
BO 3-Pos Triac
x
x
x
BO Blind Relay
x
BO PWM
x
x
x
x
x
Quality value
Description
Normal
The function operates under normal conditions.
Invalid
The function is not operating. The process value is not valid.
No Output
(DC 24 V)
Reliable operation can't be guaranteed due to low DC 24 V operating voltage. This item will
only be sent if a switching operation has to be commanded.
No Output
(AC 24 V)
Reliable operation can't be guaranteed due to missing / failed AC voltage. This item will be
modified immediately when the AC voltage fails. The output will be switched off/inactive.
Unreliable Other
BO Bistable
AC / DC24 V is not present. The “PowerDownModeAC24V” becomes active.
Remark: Ifparameter [PowerDown ModeAC24V] is set to “Keep”, the
“PowerDownModeAC24V” will not become active and the fault will not be set.
With modules from Series D, however, it is compulsory to feed AC 24 V to bus conductor
" V
" . The module always monitors this supply.
Simatic: It is also admissible to connect DC 24 V to bus conductor " V ".
Unreliable Other
AI Measure
– The voltage on G8 is below a certain level. The external device delivering the current may
be unreliable (for current measuring SignalTypes only).
– The voltage on AC / DC 24 V is below a certain level. The external device delivering the
voltage may be unreliable (for voltage measuring SignalTypes only).
Multistate Fault
Mapping error in multistate function.
Over Range
The sensor connected to the input is reading a value higher than the normal operating range.
Under Range
The sensor connected to the input is reading a value lower than the normal operating range.
Shorted Loop
The connection between the defined object and the physical device is providing a value
indicating a short circuit condition.
Open Loop The connection between the defined object and the physical device is providing a value
indicating an open circuit condition. Exception: Pt 4-wire, open circuit of a single conductor.
No Sensor
4...20 mA current measuring signal type measures no current.
Quality Value =
part of process
value
The status and quality information are coded in the process value (raw data).