BECKHOFF CX2020 - Manual (Page 39)

Error handling and diagnostics
5 Error handling and diagnostics
5.1 Basic CPU module
5.1.1 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).
TC TwinCAT status LED TwinCAT is in Run mode (green)
TwinCAT is in Stop mode (red)
TwinCAT is in Config mode (blue)
HDD Read/Write Compact Flash (red) Indicates access to the CFast card.
FB1 Status LED1 for fieldbus (function is written at the fieldbus interface)
FB2 Status LED2 for fieldbus (function is written at the fieldbus interface)
5.1.2 LEDs of the power supply unit (CX2100­0xx4) in K­bus mode
After switching on, the power supply immediately checks the connected Bus Terminal configuration. If K­bus
terminals are detected, the error­free bootup is signaled by the red “I/O ERR LED” going out. If the “I/O ERR”
LED blinks, an error in the area of the terminals is indicated. The error code can be determined from the
frequency and number of blinks. This permits rapid rectification of the error.
Display LED Meaning
Us 24 V Power supply for the CPU module. The LED lights
green if the power supply is correct.
Up 24V Power supply for terminal bus. The LED lights green if
the power supply is correct.
K­BUS
RUN K­bus diagnostics. The green LED lights up in order to
indicate fault­free operation. "Fault­free" means that
the communication with the fieldbus system is also
running.
K­BUS
ERR K­bus diagnostics. The red LED flashes to indicate an
error. The red LED blinks with two different
frequencies.
Table 9: The I/O error LED blink code
fast blinking Start of the error code
First slow sequence Error code
Second slow sequence Error code argument
CX2020, CX2030, CX2040 39 Version 1.2