SMC Networks EX245-FPS1 Operation Manual page 20

Safe state
3.3.8.
The safe state for the module is the transmission of the value "0" in the image of the inputs to the safe
controller.
The safe state for the F-Input data is "0".
Passivation results in a change to the safe state: see
The safe state can be entered in the following cases:
1. Operating state
2. Error detection in I/O devices
3. Device errors
4. Parameterization errors
5. Error detection during safe communication
Operating state
In the operating state, the inputs can enter states "1" or "0". State "0" is the safe state.
Error detection in I/O devices
Inputs
If an error is detected at an input, the safe state is set at this input and a "0" is represented in the process
image of the input ("0" = safe state).
Operating time in the error state:
If an error state is entered on the modules, this error must be assessed, acknowledged or removed by
the user within 72 hours. This action ensures the safe operating state of the module. Exceeding this
time limit is not recommended and may adversely affect the future safety performance of the unit.
In the error operating state, internal module tests are no longer run and it is possible that the safe state
may be exited due to an accumulation of errors.
Depending on the parameterization, the following errors can be detected at inputs:
Short circuit
Cross circuit
The diagnostic message is transmitted to the controller: see
Device errors
Device errors can stop safe communication.
Outputs
If an internal hardware error is detected all module outputs are disabled i.e. safe state is output
Inputs
If a hardware fault in the internal circuit is detected at an input, all module inputs enter the safe state. The
value "0" is represented in the process image of the inputs ("0" = safe state).
The diagnostic message is transmitted to the controller: see
Serious errors
All serious errors that can result in the loss of or adversely affect the safety function cause the entire
module to enter the failure state.
"Passivation" in Appendix A: glossary.
Section 16 "Error
Section 16 "Error
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No.EX##-OMY0004