Selection
Why a production line needs cabinet NTP: five must-haves
Mis-ordered PLC alarms, broken SCADA joins, wrong shift cuts, MES mismatch, and interval-energy drift are the real cabinet-NTP jobs—not a nanosecond slogan.
Updated 2026-08-22
Decision
Production trace: SY-1231. NTP/SNTP on UDP 123; otherwise Modbus millisecond calendar.
Notes
Most urgent: event trace. PLC alarms, faults, and downtime need one clock, or incident order cannot be rebuilt. NTP/SNTP PLCs point at SY-1231 (UDP 123); others poll RS-485 Modbus absolute time (1 ms).
Multi-PLC / line join: several PLCs plus SCADA or an IPC can be correlated only if timestamps match. Without a shared source, the same event splits across free-running PLC clocks.
Shift / reports: output, runtime, and energy cuts follow the clock. IPC-only time plus drifting PLC clocks scramble shift boundaries.
MES / quality: process and batch records must match the MES server. Pharma, food, and auto often audit time sync—this unit is an inspectable source, not a substitute for your MES/GMP system or a third-party certificate.
Interval energy: kWh / gas / water totals need the collecting PLC aligned with the metering system. That is interval alignment—not a legal metrology instrument or a billing certificate. Shipping SY-1231: design reply / overload protect 3840 req/s; no IRIG, no OCXO, no PTP. Prove LOCK and UDP 123, then accept per channel.
FAQ
- What is the decision?
- Production trace: SY-1231. NTP/SNTP on UDP 123; otherwise Modbus millisecond calendar.
- What are the key points?
- Mis-ordered PLC alarms, broken SCADA joins, wrong shift cuts, MES mismatch, and interval-energy drift are the real cabinet-NTP jobs—not a nanosecond slogan.