Pilz PSS SB NOT, Basic license - Manual (Page 20)

3-4
Safety
Modular Block System: Emergency Stop Circuits
Fault detection
The detection of errors and defects is an important function of the PSS, in
addition to pure control tasks.
Potential faults are subdivided into:
• Errors in the system hardware and wiring errors in the periphery units:
- Errors in the system hardware are automatically detected and managed
by the PSS
- If test signals are used, wiring errors in the periphery units will
automatically be detected and managed by the PSS.
Users do not need to take this type of error into account within the
application program (additional information can be found in the PSS
“System Description”).
• Feasibility errors and functional errors in the process periphery units
(input devices, actuators, wiring etc.).
These errors must be detected and managed through the PSS control
program.
WARNING!
It is particularly important to detect open circuits and shorts within the
safety circuits (e.g. two-hand, E-STOP etc.)
It is the responsibility of the user to select and apply an appropriate fault
detection system.