Hospital weak-current, school campus, production cabinets (alarm / SCADA / MES), industrial cabinets, security NVR, and office/metrology LANs. Order SY-1231-BG-T-S (BeiDou+GPS) or SY-1231-GN-T-S (GPS+GLONASS); TCXO, single 10/100M, NTP Stratum 1 after LOCK.

Which constellation does SY-1231 use?

Two order codes: SY-1231-BG-T-S is BeiDou+GPS; SY-1231-GN-T-S is GPS+GLONASS. Follow the nameplate / Web for the shipped option.

Does the 1231 include IRIG-B, OCXO, or PTP?

No. This SKU has no IRIG-B, OCXO, PTP/IEEE 1588, dual-NIC failover, NTS, IPv6 NTP, NTP broadcast/multicast, HTTPS, or SNMPv3. Hardware-stamped NTP / OCXO / IRIG-B → coming SY-4096.

How many NTP clients can it serve?

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

What is the factory default address?

192.168.1.123/24, gateway 192.168.1.1. NTP is UDP 123. Power is single-path -S: IEC AC 220 V or a 12–24 V DC adapter—one inlet at a time.

How should we accept it? Nanoseconds on the NIC?

Accept per channel: Ethernet NTP, Modbus (millisecond), TTL 1PPS, and minute PULSE are separate. Do not rewrite GNSS/internal edges as “nanoseconds on the NIC” or “nanosecond Modbus”. Contract against client measurement, not a factory PASS lamp.

When should we choose SY-4096 instead?

Choose coming SY-4096 when you need IEEE 1588 hardware-stamped NTP, OCXO holdover, or IRIG-B hardware time I/O on a single subnet. Use 1231 for immediate cabinet delivery. Multi-port / dual-supply plant flagship → SY-8640 (roadmap).

TemporaSync™

SY-1231

NTP Time Server · Stratum 1

Typical order model: SY-1231-BG-T-S · SY-1231-GN-T-S Shipping

Nameplate: TemporaSync · SY-1231

GNSS-disciplined LAN NTP Stratum 1 for hospital, school, industrial, and security cabinets. Constellation orders: BG = BeiDou+GPS (SY-1231-BG-T-S) or GN = GPS+GLONASS (SY-1231-GN-T-S). TCXO holdover, single 10/100M, plus Modbus / 1PPS / PULSE. No IRIG and no OCXO.

Fit Hospital weak-current, school campus (network room / teaching-building cabinet / exam and one-card), production cabinets (alarm / SCADA / MES), industrial cabinets, security NVR, office/metrology; single LAN port, tens of clients class.

Not for IEEE 1588 hardware-timestamped NTP / OCXO / IRIG-B (see SY-4096); or separated mgmt/timing ports, multi-gigabit, dual supply (see SY-8640).

Selection help Download datasheet How to choose

TemporaSync SY-1231 1U chassis front panel

Entry SKU. Delivers Stratum 1 after lock for cabinet NTP clients: single port, BeiDou+GPS, TCXO holdover; Web and SNMP read-only for checks. Typical fit: hospital weak-current, school network rooms, and mid-size LANs. Later unified-platform cutover is planned—not an in-place field upgrade of this unit.

How it differs from the other model

Ladder: SY-1231 embedded/protocol (UDP 123 + Stratum 1) → SY-4096 cabinet/capacity (2¹² slave-clock name) → SY-8640 flagship/time-origin (86400 s/day without the trailing zero). Reserved: SY-8192 (next cabinet, 2× slaves), SY-16384.

TemporaSync SY-4096 · TemporaSync SY-8640 · How to choose

Specification summary

Timing protocol	NTP v3/v4 (UDP 123)
Time reference	GNSS 1PPS + TCXO discipline; industrial RTC holdover
Constellation (two orders)	BG = BeiDou+GPS (SY-1231-BG-T-S); GN = GPS+GLONASS (SY-1231-GN-T-S). Follow the nameplate / Web
Ethernet	1× RJ45, 10/100M (single port; not dual-port redundancy)
Power	Single path -S; IEC AC 220 V or DC050-T + external adapter (12–24 V DC); one inlet at a time
Management	Web (HTTP Basic Auth) + front LCD; SNMP read-only (SNMPv2c)
Planning cap	Default 60; plan N≤min(60, η·R/f_poll) from your poll rate (η 0.5–0.7)
NTP performance	Overload protect ≤2048 req/s; design reply capacity ≈1800 req/s (16 sources)
Default IP	192.168.1.123/24, gateway 192.168.1.1
Factory traceability	Factory gate; Web production record PASS/FAIL; SETID / firmware Build on the ship ticket

Interfaces

RJ45 (NTP + Web)
RS-485 Modbus
1PPS OUT (3.3 V)
PULSE (Pin4 PPM)
GNSS antenna
LCD + key

Included

Ethernet NTP service (LAN Stratum 1 after lock)
RS-485 Modbus RTU absolute time (UTC incl. ms)
TTL 1PPS output (3.3 V, GNSS second-edge buffered)
PULSE minute PPM (4-pin Pin4; 200 ms / 5 V after LOCK)
Web UI, SNMP read-only, event log and 24h quality export
Factory test record (SETID · Build · PASS)

Not included (do not assume for tenders)

IRIG-B time code
OCXO
PTP / IEEE 1588 stack
NTS, IPv6, NTP broadcast/multicast server
Dual-port failover
HTTPS, SNMPv3, SNMP write

Important: GNSS second-edge / internal reference figures are not “nanoseconds on the NIC” or “nanosecond Modbus timing”. See accuracy layers in the datasheet.

FAQ

Who is SY-1231 for?: Hospital weak-current, school campus, production cabinets (alarm / SCADA / MES), industrial cabinets, security NVR, and office/metrology LANs. Order SY-1231-BG-T-S (BeiDou+GPS) or SY-1231-GN-T-S (GPS+GLONASS); TCXO, single 10/100M, NTP Stratum 1 after LOCK.
Which constellation does SY-1231 use?: Two order codes: SY-1231-BG-T-S is BeiDou+GPS; SY-1231-GN-T-S is GPS+GLONASS. Follow the nameplate / Web for the shipped option.
Does the 1231 include IRIG-B, OCXO, or PTP?: No. This SKU has no IRIG-B, OCXO, PTP/IEEE 1588, dual-NIC failover, NTS, IPv6 NTP, NTP broadcast/multicast, HTTPS, or SNMPv3. Hardware-stamped NTP / OCXO / IRIG-B → coming SY-4096.
How many NTP clients can it serve?: Planning cap defaults to 60; compute N≤min(60, η·R/f_poll) from the datasheet (η 0.5–0.7). Overload protect ≤2048 req/s; design reply ≈1800 req/s (16 sources). Not a data-center class box.
What is the factory default address?: 192.168.1.123/24, gateway 192.168.1.1. NTP is UDP 123. Power is single-path -S: IEC AC 220 V or a 12–24 V DC adapter—one inlet at a time.
How should we accept it? Nanoseconds on the NIC?: Accept per channel: Ethernet NTP, Modbus (millisecond), TTL 1PPS, and minute PULSE are separate. Do not rewrite GNSS/internal edges as “nanoseconds on the NIC” or “nanosecond Modbus”. Contract against client measurement, not a factory PASS lamp.
When should we choose SY-4096 instead?: Choose coming SY-4096 when you need IEEE 1588 hardware-stamped NTP, OCXO holdover, or IRIG-B hardware time I/O on a single subnet. Use 1231 for immediate cabinet delivery. Multi-port / dual-supply plant flagship → SY-8640 (roadmap).

Quality & commissioning

Factory-tested, field-checkable, traceable after sale

Specs are written per channel. Each shipping unit passes a factory gate. Commission on-site with the datasheet, Web exports, and client checklist. Contract acceptance is client measurement—not a factory PASS lamp.

Factory production test

Each SY-1231 is gated before ship: LOCK, LAN NTP, and 1PPS / PULSE / Modbus checked per channel. The Web UI shows a read-only factory record (PASS/FAIL); the ship ticket records SETID and firmware Build. Fixture thresholds stay internal; a PASS sheet without process detail can ship with the unit when required.

Commissioning kit

The datasheet and interface annex give per-channel steps: scope the 1PPS jack and Pin4 minute pulse, NTP via the client checklist, Modbus via the register map. The LCD is for patrol; accuracy and events go out as event_log.csv and quality_24h.csv. Hospital sites also have a 10-step bring-up note.

Field assistant (optional)

The Sync Assistant is a field health-check and troubleshooting helper (SNTP / client status). It is not a metrology certificate and does not change host time by default. The config command library is licensed. Ask sales. The factory gate EXE is for production only and is not a public download.

QA wording: include/exclude and accuracy layers follow the shipping datasheet. For support, send SETID + Build plus event/quality CSVs. Do not put internal second-edge figures into NIC acceptance.

NTP client checklist Download datasheet Ask for the field assistant