Beckhoff · EL2912 TwinSAFE
When LED Diag 1 is off and LED Diag 2 flashes with code 1 (400ms ON / 400ms OFF), it indicates that the internal supply voltage for microcontroller μC1 has exceeded its maximum permissible limit. This environment-related error signals an overvoltage condition, potentially risking damage to the μC1 or compromising its safety functions due to electrical stress.
Click steps to track your progress.
Measure input voltage at the power supply terminals (e.g., L1, L2) to confirm it's within specified range (e.g., 110V-230V AC).
Verify device's internal DC bus voltage, if accessible, is not exceeding its design limit.
Inspect power input terminals for signs of overheating or damage.
Disconnect external power and allow device to discharge before re-applying power.