Model 1094B GPS Substation Clock (250 ns)

Combining world-class accuracy with value pricing, Model 1094B delivers as standard the most commonly requested features for substation applications in Arbiter’s line of precision timing products.

Standard features include a 12 channel GPS receiver with typical accuracy to < ±100 ns, two serial communications ports, and four standard outputs supporting both BNC and 5 mm terminal strip connections, selectable to output IRIG-B, 1 PPS or programmable pulse A or B functions. Able to output 5 Vdc, the unit can easily drive multiple loads in parallel, including synchrophasors. GPS Data Backup battery capable of maintaining the real-time clock, almanac and ephemeris data in the case of power loss.

  • 19” Rack unit, 1 RU high
  • Accuracy < ±100 ns typical; < ±250 ns worst case
  • Four outputs configurable for BNC or 5mm terminal strip connectors
  • IRIG-B outputs
  • 1 PPS output
  • One Form C (SPDT) fail-safe relay
  • Two RS-232 and RS-422/485 ports available


Receiver Characteristics

Timing Accuracy

Accuracy Note Specifications apply at the 1 PPS output, in the presence of Selective Availability (SA), as of date of publication.
Accuracy UTC/USNO ± 250 ns peak; < ± 100 ns typical (SA off)

Satellite Tracking

Twelve (12) channel, C/A code (1575.42 MHz). Receiver simultaneously tracks up to twelve satellites.


  • 150 seconds typical, cold start
  • 15 minutes, 90 % confidence, cold start
  • 40 seconds, with almanac less than 1 month old
  • 15 seconds, with ephemeris less than 4 hours old

I/O Configuration

Output Connectors

Four, each with BNC and 5 mm pluggable terminal strip in parallel.

Output Signals

Jumper selectable to high-drive 5 Vdc (250 mA at > 4 V) selectable to:

  • IRIG-B00x level-shift,1 PPS orProgrammable Pulse A or B
  • IRIG-B12x modulated
  • 300 volt MOSFET output.

The MOSFET output is selectable to the same functions as the high drive 5 Vdc output. The MOSFET output is not electrically isolated from instrument common.

Input Connectors

Event A Input:

One opto-isolated event capture input with 100 ns resolution, BNC connector jumper-configurable to 5 Vdc to 12 Vdc, 24 Vdc to 48 Vdc and 120 Vdc to 240 Vdc nominal input. Event input is also jumper-configurable to COM 1 and COM 2 RXD line.

Programmable Pulse Output

Two programmable pulse outputs, PPA and PPB. PPA is available (by a jumper connection) on outputs 1, 2 and COM 1 pin 4 (RS-232) and pins 8 and 9 (RS-485). PPB is available (by a jumper connection) on outputs 3, 4 and COM 2 pin 4 (RS-232) and pins 8 and 9 (RS-485).

Six modes:

  • Every 1 second to 60,000 seconds, starts top of the minute
  • Hourly at a specified offset
  • Daily at a specified time of day
  • One shot at a specified time of year
  • 1 PPS to 1000 PPS squarewave (PPB only)
  • Aux IRIG Mode (PPB only)

Pulse duration is programmable from 0.01 seconds to 600 seconds, except in one-shot mode, where the output is Low prior to the specified time and High thereafter.

Relay Contacts

One, Form C (SPDT) fail-safe, 0.3A at 130 Vdc; jumper selectable to Fault, Unlocked, or Programmable Pulse A (PPA) functions. Fail-safe means the relay indicates ”fault” or ”unlocked” condition with power off.



  • 2 character x 20 character supertwist LCD
  • White LED backlight
  • Time: UTC or local
  • Position: latitude, longitude, elevation
  • Clock status
  • 1 PPS (input) deviation
  • Event time
Status LEDs
  • Operate (green)
  • Stabilized (green)
  • Unlocked (red)
  • Fault (red)
Keyboard Eight keys
  • Local time offset
  • IRIG-B: Local/UTC/1344
  • Daylight Saving Time: On/Off/Auto
  • Backlight control: On/Off/Auto
  • Event input: Event/1 PPS deviation
  • Programmable Pulse setup
  • Antenna cable delay
  • Out of lock time: 1 minute to 99 minutes, Off, or Zero Delay
  • Auto-Survey
  • Serial port: RS-232


RS-232 1200 baud to 38,400 baud; 7 or 8 data bits; 1 or 2 stop bits; even/odd/no parity
RS-422/485 Transmit only, to drive multiple devices. Two outputs. Uses extra pins on Com 1 and Com 2.
Broadcast modes
  • Standard ASCII (IRIG-J)
  • Extended ASCII
  • ASCII with Time Quality
  • ASCII with Time Quality and Year
  • Vorne large-display time
  • Status
  • Event
Connector 2 Male 9-pin D-sub Com 1 and Com 2(TXD, RXD, AUX IN, AUX OUT)

Power Requirements


Voltage (Option 07) 85 Vac to 264 Vac, 47 Hz to 440 Hz, 20 VA maximum or 110 Vdc to 370 Vdc, 15 W maximum
Inlet (Option 07) IEC-320 with fuse and mating cordset. Specify option P01 – P10

Available cordset plug style and specifications are described in the Options and Accessories section.



Size 1 RU rack mount or tabletop, 260 mm deep FMS, Rack mounts included.
508 mm x 381 mm x 203 mm (20 in x 15 in x 8 in), shipping
Weight 2 kg (4.5 lbs), net
5.5 kg (12 lbs), shipping
Antenna Cable Connection: F-type
Size: 80 mm hex (across flats) x 84 mm tall (3.2 in x 3.3 in), including connector
Weight: 170 g (6 oz)
Antenna Cable Type: RG-6, 15 m (50 ft) provided
Weight: 0.69 kg (1.52 lbs) per 15 m
Antenna Mounting 0.75 in pipe (1 in – 14 marine) thread


Temperature Operating: 0 °C to + 50 °C (- 20 °C to + 70 °C typical)

Nonoperating: – 40 °C to + 85 °C

Humidity Noncondensing
EMC Radiated susceptibility: passes walkie-talkie test.

Conducted emissions: power supply complies with FCC 20780, Class A and VDE 0871/6.78 Class A.

Surge withstand capability (SWC), power inlet: designed to meet ANSI/IEEE C37.90-1 and IEC 801-4

Certificates and Approvals

CE mark/label and certificate