ALARM 2000: PLC sign-of-life monitoring in Siemens 828 d
Alarm 2000 on SINUMERIK 828D: PLC Sign‑of‑Life Monitoring Alarm 2000 on a SINUMERIK 828D indicates that the NCK stopped receiving the PLC’s cyclic “sign‑of‑life” heartbeat within the configured timeout, so the control blocks NC start and transitions to a safe stop until…