BECKHOFF CX9020 - Manual (Page 38)

Error handling and diagnostics
5 Error handling and diagnostics
5.1 LEDs on the basic CPU module
Display LED Meaning
PWR Power supply The Power LED comes on when the
device is connected to a live power supply unit
(green).
The LED blinks fast (red) if there is a power failure.
The LED blinks slow (red) if there is no or an
incorrect µSD card inserted.
TC TwinCAT status LED TwinCAT is in Run mode
(green)
TwinCAT is in Stop mode (red)
TwinCAT is in Config mode (blue)
FB1 Status LED1 for fieldbus (function is written at the
fieldbus interface)
FB2 Status LED2 for fieldbus (function is written at the
fieldbus interface)
HDD 1 Indicates access to the µSD card in slot 1. LED
flashes green during read access.
LED flahes yellow during write access.
HDD 2 Indicates access to the µSD card in slot 2. LED
flashes green during read access.
LED flahes yellow during write access.
CX9020 38 Version 1.1