Status LEDs and Control Elements

RUN/STOP switch

The processor module PM55x-xP and PM56x-xP contain a RUN/STOP switch which can be set with a small screwdriver. In the RUN position, the program loaded in the processor module will be executed and in the STOP position it will be stopped.

When COM1 and COM2 are not in online access mode, the user program can only be changed, uploaded and downloaded if the RUN/STOP switch is in STOP position.

Status LEDs

The processor modules PM55x-xP and PM56x-xP show their status of operation via 3 LEDs located in the left upper edge of the processor module.

LED	Status	Color	LED = ON	LED = OFF	LED flashing
PWR	Power supply	Green	Power supply present	Power supply missing	–
RUN	RUN/STOP Status	Green	Processor module is in status RUN	Processor module is in status STOP	Fast flashing (4 Hz): The processor module is reading/writing data to the SD Memory Card. If the ERR-LED is also flashing, data is written to the Flash-EEPROM. Slow flashing (1 Hz): The firmware update from the SD Memory Card has been finished successfully.
ERR	Error indication	Red	An error occurred	No errors or only warnings encountered (E4-errors). The LED behaviour by the error classes 2 to 4 is configurable.	With 4 Hz (fast): displays together with the RUN LED a currently running firmware-upgrade or writing data to the Flash-EPROM.

I/O LEDs

Each processor module contains up to 15 LEDs (depending on type) to display the statuses of the inputs and outputs.

Processor module	LED	Status	Color	LED = ON	LED = OFF
PM55x-xP PM56x-xP	I0 … I7 (PM55x-xP) I0 … I5 (PM56x-xP)	Digital input	Yellow	Input is ON	Input is OFF
	O0 … O5	Digital output	Yellow	Output is ON	Output is OFF
PM56x-xP	AI0, AI1*	Analog input	Yellow	Input is ON	Input is OFF
	AO	Analog output	Yellow	Output is ON	Output is OFF

* The analog inputs AI0 and AI1 can be configured as digital input or analog input.

Status LEDs at Ethernet Connector (-ETH models only)

LED	Color	OFF	ON	Flashing
Activity	Yellow	No activity	—	Activity
Link	Green	No link	Link	—