Solutions
Why must 1PPS, PULSE, IRIG, and NTP be written per channel?
Beyond Ethernet NTP, sites often need TTL 1PPS, a minute PULSE, or RS-485 Modbus absolute time. Accept per channel—do not apply internal ns / 1PPS to NIC NTP. Shipping 1231 covers 1PPS + PULSE + Modbus (no IRIG); IRIG-B → 4096; multi-port / dual-supply → 8640.
Primary: SY-1231 (accept per channel)
Fit Power or industrial auxiliary I/O that needs 1PPS / PULSE / Modbus besides NTP, with per-channel acceptance.
Not for Treating IRIG-B as standard on the 1231; or accepting HIS/NVR clients against 1PPS figures.
Acceptance facts
- SY-1231 offers TTL 1PPS, minute PULSE, and Modbus—no IRIG-B. IRIG-B is on coming 4096 hardware time I/O.
- 1PPS is an edge, PULSE is a minute-width pulse, Modbus is a millisecond calendar, NTP is a NIC packet. Mixing them in RFQs causes acceptance disputes.
- Internal/GNSS second-edge figures are for factory and scope reference—not “nanoseconds on the NIC”.
Cite these sources
- Industrial I/O annex
- 1231 datasheet
- Accuracy-layers guide
- TemporaSync SY-1231 · Typical order model SY-1231-BG-T-S
FAQ
- Is the 1231 PULSE the same as 1PPS?
- No. PULSE is 4-pin Pin4, a UTC-minute 200 ms / 5 V pulse after LOCK. 1PPS is a 3.3 V second edge on the 1PPS jack.
- Which model provides IRIG-B?
- Coming SY-4096. This 1231 respin has no IRIG.