Diagnostic LEDs

PWR

Power supply
The power LED lights green if the device is connected to a power supply unit and the unit is switched on.

Die SUPS is active (violet).

Bootloader is started and runs without errors (the colors red and yellow light up for one second).

TC

TwinCAT status LED
TwinCAT is in Run mode (green)
TwinCAT is in Stop mode (red)
TwinCAT is in Config mode (blue)

Error or crash of the PLC (yellow). Applies only to TwinCAT 3

FB1

Status LED1 for fieldbus (the function is described under the fieldbus interface)

FB2

Status LED2 for fieldbus (the function is described under the fieldbus interface)

U1

User LED for free use. The RGB LED is switched by the function block FB_SetLedColorEx_BAPI.

Use the user LEDs, for example, to make the states of the PLC program, communication or other indications externally visible.

HDD

Read/Write storage medium
(red) Indicates an access to the storage medium.