Electrical Installation      59- 
4.2  Example for a Fail-Safe monitoring of the PI with a PLC 
 
Figure 35: Fail-Safe monitoring states 
Fail-Safe monitoring states 
Breakdown of PIF power supply 
Cable break of fail-safe cable 
Breakdown of PI power supply/ Interruption of USB cable 
Interruption of cable PI-PIF 
Malfunction of PIX Connect software