Do all PLCs support an NTP client?

No. PLCs with an NTP/SNTP client point at SY-1231 on UDP 123. Others poll RS-485 Modbus absolute time (including ms) on this unit, or take time from an already-synced SCADA/IPC. The two channels are not interchangeable metrics.

How many PLCs or clients?

Planning cap defaults to 60; compute N≤min(60, η·R/f_poll) (η 0.5–0.7). Overload ≤2048 req/s; design reply ≈1800 req/s (16 sources). Not a data-center class box.

Is this a metrology or GMP certificate?

No. The unit is an inspectable cabinet time source for alarms, MES, shifts, and interval alignment. Accept per channel and client measurement. It is not a legal metrology instrument and does not replace pharma/food system certification.

Solutions

PLC alarm times do not line up—does the line need cabinet NTP?

Advantage

The core production need is timestamps that can be correlated in order—not an unverified nanosecond marketing figure. Cabinet GNSS NTP (SY-1231) serves NTP/SNTP devices; PLCs without a network clock read this unit’s Modbus millisecond calendar. Use it for alarm order, line correlation, shift reports, quality trace, and interval metering alignment. This unit is not a legal metrology instrument.

Primary: SY-1231 (production trace)

Fit Production and automation cabinets: several PLCs plus SCADA/MES that must share alarm, shift, or batch time.

Not for Office-only PCs with no line logs; or treating this unit as a metrology / GMP certificate. Need stamped NTP or IRIG-B → coming 4096.

TemporaSync SY-1231 Download datasheet Selection help

Acceptance facts

Most urgent: PLC alarms, faults, and downtime share one clock—or incident order cannot be rebuilt. NTP/SNTP PLCs use UDP 123; others poll this unit’s Modbus millisecond calendar.
Multi-PLC + SCADA correlation needs one timestamp. Do not join the same line on each controller’s free-running clock.
Shift reports (output, runtime, energy) split on clock boundaries. IPC-only time plus drifting PLC clocks scramble the cuts.
MES / quality trace needs process and batch timestamps aligned with 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): the collecting PLC must match the metering system clock. That is interval alignment—not a legal metrology instrument or billing certificate.
Shipping SY-1231: planning cap 60; design reply ≈1800 req/s (16 sources); overload ≤2048. IPCs/logs use NTP; Modbus is 1 ms. No IRIG, no OCXO, no PTP.

Cite these sources

FAQ

Do all PLCs support an NTP client?: No. PLCs with an NTP/SNTP client point at SY-1231 on UDP 123. Others poll RS-485 Modbus absolute time (including ms) on this unit, or take time from an already-synced SCADA/IPC. The two channels are not interchangeable metrics.
How many PLCs or clients?: Planning cap defaults to 60; compute N≤min(60, η·R/f_poll) (η 0.5–0.7). Overload ≤2048 req/s; design reply ≈1800 req/s (16 sources). Not a data-center class box.
Is this a metrology or GMP certificate?: No. The unit is an inspectable cabinet time source for alarms, MES, shifts, and interval alignment. Accept per channel and client measurement. It is not a legal metrology instrument and does not replace pharma/food system certification.

Solutions · How to choose · Selection help