BECKHOFF KL1904 - Manual (Page 31)

Operation
KL1904 29
4.3 Diagnostics
4.3.1 Diagnostic LEDs
4.3.1.1 Diag 1 (green)
The Diag 1 LED indicates the state of the TwinSAFE interface.
Flashing Code Meaning
LED illuminated continuously
(from firmware version 17) or
cyclic flashing at 1 Hz
(up to firmware version 16) normal operation:
TwinSAFE communication OK
rapid flickering, alternating with 1 flash pulse Error in S parameter (TwinSAFE parameter)
rapid flickering, alternating with 2 flash pulses Error in I parameter (Individual parameter)
rapid flickering, alternating with 3 flash pulses Waiting for S and I parameter
rapid flickering, alternating with 4 flash pulses S- and I-parameter correct:
waiting for first host message
rapid flickering, alternating with 5 flash pulses Watchdog error
rapid flickering, alternating with 6 flash pulses CRC error
rapid flickering, alternating with 7 flash pulses Sequence number error
rapid flickering, alternating with 8 flash pulses Intermediate state in a sensor
4.3.1.2 Diag 2 (red)
The Diag 2 LED illuminates red if the terminal detects an external supply or cross-circuit. The LED
extinguishes once the error is rectified.