Model 120A GNSS Synchronized Clock (100ns)

Next generation multi-satellite timing source for precision applications that require a compact package.

Model 120A User Manual
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Model 120A User Manual Español
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Model 120A Setup Guide
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Model 120A Setup Guide Español
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Model 120A Data Sheet
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Model 120A Data Sheet Español
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The Model 120A GNSS Synchronized Clock is a multi-satellite system (GPS, Galileo, GLONASS, BeiDou) timing source. Designed as an economical solution for reclosers and other enclosed installations, includes a rugged, low-profile, bulkhead-mount antenna with 5 meters of cable.

The Model 120A has a seventy-two channel receiver, capable of tracking up to 3 satellite constellation systems simultaneously providing a 100 ns rms accuracy.

Two pluggable terminal strip outputs provide IRIG-B unmodulated, 1 PPS, or Programmable Pulse; software selectable. These outputs are configurable to a 50 ohm driver or a high capacity driver. The Model 120A comes standard with two communication ports, one RS-232 and one USB. A SPST relay is also included and is configurable to Out of Lock, Fault, Alarm, Stabilized, or Programmable Pulse.

Low-voltage dc power input accepts + 8 Vdc to + 32 Vdc.

Five year limited warranty from date of delivery.

Key Features
Specs
Options
Accessories
Software
Firmware
Related Resources

Accuracy of ± 100 ns rms
Two outputs, software selectable signals:
- Unmodulated IRIG-B
- 1 PPS
Two outputs, software selectable drive capability:
- 50 ohm
- High-drive (125 mA)
One Form A (SPST) fail-safe relay: 0.12 A at 400 Vdc (400 mW)
Low dc power input: + 8 Vdc to + 32 Vdc

Enhancements

Multi-system timing sources (GPS/ GLONASS/Galileo/BeiDou).
Micro-USB management port.
Configured through command-line interface.
Xmodem Firmware updates.
Wide operating temperature range.
IRIG-B compliant with IEEE Std. C37.118.1-2011 Synchrophasor use.

Receiver Characteristics

Timing Accuracy

Accuracy Note	Specifications apply at the output when receiving satellite signals, as of date of publication.
Accuracy UTC/USNO	± 100 ns rms

Position Accuracy

2 meters, rms

Satellite Tracking

Seventy-two (72) channel receiver: GPS L1C/A, GLONASS L1OF, Galileo E1B/C, and BeiDou B1I

Acquisition

50 seconds typical, cold start
25 seconds, typical, hot start

I/O Configuration

Output Connectors

One 12-position pluggable terminal strip:

Out 1: IRIG-B unmodulated, 1 PPS or Programmable Pulse; software configurable
Out 2: IRIG-B unmodulated, 1 PPS or Programmable Pulse; software configurable
RS-232: Transmit, Receive, and Ground
Relay: SPST fail-safe, 0.12 A at 400 Vdc (400 mW); software configurable
Power

USB micro connector
USB 2.0 serial port emulation, supports terminal configuration and firmware updates
F-Connector
Antenna, 5 Vdc compatible

Programmable Pulse Output

Two programmable output pulses (Out 1 and Out 2) with software selectable drive capability.

50 ohm
High-drive (125 mA)

Five signal modes:

IRIG-B unmodulated (UTC/Local, C37.118.1 On/Off.)
Every 1 second to 999 seconds
Hourly at a specified offset
Daily at a specified time of day
DCF-77

Relay Contacts

One Form A (SPST) fail-safe, 0.12 A at 400 Vdc (400 mW); configurable to Out-of-Lock, Fault, or Programmable Pulse

Interface

Operator

Status LEDs	Locked (green) Power (green) Unlocked (red) Fault (red)

System

USB	Management and configuration. Terminal emulation: 115,200 baud; 8 data bits; 1 stop bit; no parity
RS-232	1200 baud to 115,200 baud; 7 or 8 data bits; 1 or 2 stop bits; even/odd/no parity Pluggable terminal strip (TxD, RxD, GND) Configuration and Broadcast modes
Broadcast modes	Standard ASCII (IRIG-J) Vorne Extended ASCII ASCII with Time Quality ASCII with Time Quality and Year Custom NEMA $GPGLL NEMA $GPZDA
Connector	Pluggable terminal strip

Power Requirements

Standard

Voltage	+ 8 Vdc to + 32 Vdc, 5 W maximum
Inlet	Pluggable terminal strip

General

Physical

Size	110 mm x 85 mm x 30 mm (4.3 in x 3.4 in x 1.2 in), mounting flanges included 254 mm x 152 mm x 102 mm (10 in x 6 in x 4 in), shipping
Weight	0.45 kg (1 lbs), net 0.9 kg (2 lbs), shipping
Antenna	Cable Connection: TNC Size: 60 mm dia. x 30 mm (2.4 in x 1.2 in) Weight: 125 g (4.4 oz) Temperature: - 40 °C to + 85 °C
Antenna Cable	RG-174/U, 5 m (16 ft) provided Weight: 85 g (3 oz)
Antenna Mounting	Bulkhead (0.8 in threaded nut)

Environmental

Temperature	Operating: - 40 °C to + 85 °C
Humidity	Noncondensing

Certificates and Approvals

CE mark/label and certificate

There are no additional Options available for this product.

Included
AS0111600	GPS Antenna with 5 m (16 ft) Cable
PD0058300	Setup Guide (120A)
Available
AP0003400 ¹	BNC (Male) Breakout to 100 mm Wires
AP0008900 ²	BNC (Female) Breakout to 100 mm Wires
AP0014900 ³	BNC (Female) Breakout to Screw Terminal
AP0015000 ⁴	BNC (Male) Breakout to Screw Terminal
AS0094500 ⁵	GNSS Surge Arrester
AS0099200 ⁶	Arbiter Universal GNSS Antenna
CA0021306 ⁷	6 m (20 ft) RG-6 Antenna Cable, RoHS
CA0021315 ⁸	15 m (50 ft) RG-6 Antenna Cable, RoHS
CA0021330 ⁸	30 m (100 ft) RG-6 Antenna Cable, RoHS
CA0021375 ⁸	75 m (250 ft) RG-6 Antenna Cable, RoHS
CA0033700	Micro USB Cable, 6 ft
CN0032100	Adapter Female Type-F to Male TNC

¹ Converts female BNC-terminated coaxial cable to pair of wires.
² Converts male BNC-terminated coaxial cable to pair of wires.
³ Converts pair of wires to female BNC.
⁴ Converts pair of wires to male BNC.
⁵ Use with the AS0099200 GNSS antenna.
⁶ Available to use when the AS0111600 antenna will not be mounted on the cabinet and for longer cable runs.
⁷ Use with the AS0099200 GNSS antenna and the Surge Arrester. Custom lengths available from 0.3 m (1 ft) to 300 m (1000 ft). Contact factory.
⁸ Use with the AS0099200 GNSS antenna. Custom lengths available from 0.3 m (1 ft) to 300 m (1000 ft). Contact factory.

No software downloads available for this product

Related Software Information

The Model 120A has an internal user interface. Use any terminal program with Xmodem capability for full function.

Firmware Information (EPROM based firmware is not available for download)
120A_Firmware_02Mar2023_0105	Downloadable. Use the embedded user interface to import file into unit.
120A_Firmware_SHA256_02Mar2023_0105	120A_Firmware SHA256 checksum

Firmware Version and Related Information

Downloadable Firmware (120A_Firmware)

Version	Rev Level	Version Notes
02Mar2023	01.05	Updates are not security related. Changed PPH pulse width from 1 second to 2 seconds. Fixed PPH and PPD delay setting so it would stay zero. These signals do not have this capability in the 120A. Internal changes to improve operation. Posted to web site: 03 March 2023
12May2021	01.04	Updates are not security related. Fixed: Potential for data corruption on serial port located on terminal block. Did not affect the USB port data. Posted to web site: 02 June 2021
09Sep2020	01.03	Updates are not security related. Fixed: Now returns the correct position information. Bug introduced in 1.02 Posted to web site: 09 September 2020
22Jul2020	01.02	NOTE: This version has a known position data bug that is fixed in version 1.03. Updates are not security related. Fixed: Xmodem CRC send mode (CRC needed to be initialized to 0). Fixed: Single trigger now takes DST mode into account. Fixed: Relay mode where "open" configuration still allowed prog pulse modes to continue. Added GPS week rollover features to future proof the design. Added check of FPGA version and mark as missing if error. Made output line endings consistent (CR-LF). Changed "PPx" to "Outx" in status message. Now matches the new configuration commands. Increased relay PPM, PPH, and PPD pulse width to 1 second. Code updates for factory configuration. Posted to web site: 22 July 2020
27April2020	01.01	Updates are not security related. Update default username/password to make NERC-CIP compliant. Command "pp" changed to "output". Commands "inconfig" and "outconfig" changed to "writeconfig" and "readconfig". Update UI to make it more consistent throughout. Add bootloader missing indication to firmware output. Add reset after successful loading of EEPROM configuration. Relay now responds to manual open command (BZ996). Mark corrupt audit log records. Improved receiver communication and drift behavior. Posted to web site: 29 April 2020

120A_Firmware_SHA256

Version	Rev Level	Version Notes
02Mar2023	01.05	Updated to correspond with new firmware release: m120_fw_v0105.bin
12May2021	01.04	Updated to correspond with new firmware release: m120_fw_v0104.bin
09Sep2020	01.03	Updated to correspond with new firmware release: m120_fw_v0103.bin
22Jul2020	01.02	Updated to correspond with new firmware release: m120_fw_v0102.bin
27April2020	01.01	Updated to correspond with new firmware release: m120_fw_v0101.bin

GPS Substation Clock Requirements
Download gps_substation_clock_requirements.pdf (25 kB) »

IRIG-B Time Code Accuracy, IED and System Design Issues
Download irig_accuracy_and_connection_requirements.pdf (31 kB) »

Time in the Power Industry: How and Why We Use It
Download TimeInThePowerIndustry.pdf (407 kB) »

Specifying Holdover Performance
Download PD0057900_Specifying_Holdover_Performance.pdf (1 MB) »

Model 120A CE Declaration
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Antenna Cable Assemblies RoHS2 Declaration of Conformity
Download Antenna_Cable_Assemblies_RoHS2_DoC.pdf (286 kB) »