Fanuc Lkg Alarm · Must Read

| Step | Action | |------|--------| | 1 | CNC sends a latch command to the servo amplifier (via FSSB – FANUC Serial Servo Bus). | | 2 | Servo DSP (Digital Signal Processor) arms the latch circuit to capture the current position counter value on the next rising edge of the latch input signal (e.g., ESP , SKIP , PC latch ). | | 3 | After latch occurs, the servo compares with expected position (calculated from command pulse count). | | 4 | If difference > LKG tolerance parameter (pulse count) after the latch window expires → LKG alarm . |