X20(c)SA4430
14
Data sheet V1.141 X20(c)SA4430 Translation of the original documentation
8.2 Wiring errors
The wiring errors described in the following section are indicated by the red channel LED according to the appli-
cation.
If a module detects an error, then:
•
The channel LED is lit constantly red.
•
Status signal (e.g. (Safe)ChannelOK, (Safe)InputOK, (Safe)OutputOK, etc.) is set to (SAFE)FALSE.
•
Signal "SafeDigitalInputxx" or "SafeDigitalOutputxx" is set to SAFEFALSE.
•
An entry is generated in the logbook.
Danger!
Recognizable errors are detected by the module within the error detection time. Errors not recognized
by the module (or not recognized on time) that can lead to safety-critical states must be detected using
additional measures.
Danger!
It is your responsibility to ensure that all necessary repair measures are initiated after an error occurs
since subsequent errors can result in a hazard!
Errors
Detection
Comment
Open line
Detected
Module switches to the FAILSAFE state
Short circuit between T+ or T- and external 24
V or GND
Not detected
Signal distortion usually does not result due to the electrical isolation of the channels;
nevertheless, it is mandatory to use shielded signal lines.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Signal and supply lines must be installed in such a way that fault exclusion is possible
per EN ISO 13849-2:2012, table D.5.
Short circuit between T+ and T-
Not detected
This error results in signal distortion that may be detected by dual-channel evaluation in
some circumstances.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Signal and supply lines must be installed in such a way that fault exclusion is possible
per EN ISO 13849-2:2012, table D.5.
Reverse polarity of T+ and T-
Not detected
This error results in signal distortion that may be detected by dual-channel evaluation in
some circumstances.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Signal and supply lines must be installed in such a way that fault exclusion is possible
per EN ISO 13849-2:2012, table D.5.
Disturbance voltage
Not detected
This error results in signal distortion that may be detected by dual-channel evaluation in
some circumstances.
Shielded cables are mandatory for all signal lines.
Different installation paths must be used for the cabling of both signals of the signal pair.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Table 8: Error detection for safe inputs of type "Thermocouple"
Errors
Detection
Comment
Open circuit on Sense+ or Sense-
Detected
Channel errors
Short circuit between Sense+, Sense- and ex-
ternal 24 V or GND
Not detected
Signal distortion usually does not result due to the electrical isolation of the channels;
nevertheless, it is mandatory to use shielded signal lines.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Signal and supply lines must be installed in such a way that fault exclusion is possible
per EN ISO 13849-2:2012, table D.5.
Short circuit between Sense+ and Sense-
Detected
Channel errors
Disturbance voltage
Not detected
This error results in signal distortion that may be detected by dual-channel evaluation in
some circumstances.
Shielded cables are mandatory for all signal lines.
Different installation paths must be used for the cabling of both signals of the signal pair.
The user must take appropriate measures to ensure that this error does not lead to a
safety-critical state.
Table 9: Error detection for safe inputs of type "PT100 / PT1000"
