Model 1094B GPS Substation Clock (250 ns)

Model 1094B GPS Substation Clock (250 ns)

Includes the most commonly requested features and accuracy ratings for typical substation applications, all at a competitive price point.


Model 1094B User Manual
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Model 1094B Quick Setup Guide
Download PDF(586 kB) »

Model 1094B Data Sheet
Download PDF(654 kB) »

Model 1094B Data Sheet Español
Download PDF(313 kB) »

GPS Antenna Data Sheet
Download PDF(4 MB) »

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 Back Up battery capable of maintaining the real-time clock, almanac and ephemeris data in the case of power loss.

  • Accuracy < ± 100 ns typical; < ± 250 ns worst case
  • Four outputs configurable for BNC or 5mm terminal strip connectors
  • One Form C (SPDT) fail-safe relay
  • Two RS-232 and RS-422/485 ports available
  • IEEE C37.118.1-2005 compliant for Synchrophasor use.

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)

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



1200 baud to 38,400 baud; 7 or 8 data bits; 1 or 2 stop bits; even/odd/no parity


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

2 Male 9-pin D-sub Com 1 and Com 2(TXD, RXD, AUX IN, AUX OUT)

Power Requirements



(Option 07) 85 Vac to 264 Vac, 47 Hz to 440 Hz, 20 VA maximum or 110 Vdc to 370 Vdc, 15 W maximum


(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.




1 RU rack mount or tabletop, 260 mm deep FMS, Rack mounts included.
635 mm x 381 mm x 229 mm (25 in x 15 in x 9 in), shipping


2 kg (4.5 lbs), net
5.5 kg (12 lbs), shipping


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



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

Nonoperating: - 40 °C to + 85 °C




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

The available power options are listed below and are described in the Options and Accessories section, see our Product Catalog.Options and Accessories Options and Accessories section.

1094Bopt07 IEC-320 Power Inlet 85 Vac to 264 Vac RMS, 110 Vdc to 370 Vdc
1094Bopt08 10 Vdc to 60 Vdc Terminal Power Strip and Surge Withstand
1094Bopt10 85 Vac to 250 Vac RMS, 110 Vdc to 350 Vdc Terminal Power Strip and Surge Withstand
AS0028200 19 Inch Rack Mount Kit
AS0087800 Arbiter GPS Active Timing Antenna
CA0021315 1 15 m (50 ft) RG-6 Antenna Cable, RoHS
P01 - P10 2 Country specific power cord with straight female end
PD0052800 Quick Setup Guide (1094)
AP0003400 3 BNC (Male) Breakout to 100 mm Wires
AP0008900 3 BNC (Female) Breakout to 100 mm Wires
AP0013400 GPS Antenna Cable Splitter, F-Type, 950-2150 MHz, One Port Pass DC
AP0014900 3 BNC (Female) Breakout to Screw Terminal
AP0015000 3 BNC (Male) Breakout to Screw Terminal
AS0033100 Rack Slide Kit
AS0044600 Antenna Mounting Kit
AS0044700 4 21 dB In-Line Pre-amplifier
AS0048900 Antenna Grounding Block Kit, RoHS
AS0056600 24 Inch Rack Mount Kit
AS0083400 Operation Manual (1094)
AS0094500 GNSS Surge Protector
CA0019806 RS-232 Null Modem Cable, DB9F-DB9F, 2 m (6 ft) length
CA0021302 1 2 m (6 ft) RG-6 Antenna Cable, RoHS
CA0021306 1 6 m (20 ft) RG-6 Antenna Cable, RoHS
CA0021330 1 30 m (100 ft) RG-6 Antenna Cable, RoHS
CA0021345 1 45 m (150 ft) RG-6 Antenna Cable, RoHS
CA0021360 1 60 m (200 ft) RG-6 Antenna Cable, RoHS
CA0021375 1 75 m (250 ft) RG-6 Antenna Cable, RoHS
CA0026000 5 Power Cord IEC-320 to Bare Leads
CN0027800 Type F, Male, RG-11 Antenna Cable Crimp-on Connector
CN0050700 Type F, Male, RG-6 Antenna Cable Compression Connector, RoHS
CN0050800 6 Type F, Male, RG-6 Plenum Rated Antenna Cable Compression Connector, RoHS
TF0006000 Type F, RG-11 Antenna Cable Crimp Tool
TF0013200 Antenna Cable Stripping Tool, RG-6
TF0013300 Antenna Cable Stripping Tool, RG-11
TF0024000 Type F, RG-6 Antenna Cable Compression Tool
WC0004900 1 300 m (1000 ft) Roll RG-11 Cable
WC0005000 1 300 m (1000 ft) Roll RG-6 Cable
WC0005200 7 300 m (1000 ft) Roll RG-6 Plenum Rated Cable

1 Stocked length. Custom lengths available from 0.3 m (1 ft) to 300 m (1000 ft). Contact factory.
2 Only applies if Power Option 07 is ordered
3 Converts pair of wires to BNC.
4 Used for cable lengths greater than: RG-6 75 m (250 ft) ; RG-11 120 m (400 ft)
5 Used with Option 07.
6 Indoor use only. Not weather resistant. Not UV radiation protected.
7 Stocked length. Custom lengths available from 0.3 m (1 ft) to 300 m (1000 ft). Contact factory. Indoor use only. Not weather resistant. Not UV radiation protected.

Click to Download Latest Version of Software
1094_Utility_09Feb2016_1200 View and modify configuration settings.
109x_Loader_08Mar2013_0101 Used to upload firmware specific to Models 1094 and 1095.
109x_Loader_ZIP_08Mar2013_0101 Used to upload firmware specific to Models 1094 and 1095. This is the zipped executable directory.
Arbiter Time Service_01Jan2010_1500 PC Clock Synchronization Service for WIN NT/2000/XP/Vista/7. Not compatible with WIN 8.
Tera Term_01Jan2010_23 This is a very good HyperTerminal replacement. Able to capture data from Models 930A and 931A. Also able to program the GPS Satellite Controlled Clocks via serial commands.


Software Version and Related Information

1094 GUI Utility Software (1094_Utility)

The software interface specifically written for the Model 1094B.

  • Allows configuration of Model 1094B
  • Supports viewing and modification of existing configuration on Model 1094B from your PC.
  • Saves the existing configuration file from the 1094B to your PC.
  • Compatible with Windows XP, Vista, 7, 8, 10
VersionRev LevelVersion Notes
  1. Updated version to 1.2
  2. Updated copyright to 2016
  3. Minor fix for baud rate support
  4. Support new processor fast mode during firmware uploading

Note: Please be sure to update to the 1094Utility.exe to v1.2 prior to installing the latest firmware on your Arbiter 1094 clock. This updated version of the utility fixes a communication problem when uploading the latest firmware.


Completely rewritten to work better with newer Windows operating systems.


  1. Migrated changes in 1095 to 1094. (BZ 579 and 580)
  2. Non abbreviated strings for Prog Pulse Mode, Prog Pulse Type.
  3. UI layout change - Frequency dropdown box now show/hides in place of Type, Polarity, Time Selection

Firmware uploader for Models 1094 and 1095 (109x_Loader)

VersionRev LevelVersion Notes
08Mar2013 0101
  1. Supports both processor types.
  1. 109x uploader typo (Change "Coose" to "Choose"). (BZ 606)
  2. Update Linux serial port search to work with Debian

Firmware uploader for Models 1094 and 1095 (109x_Loader_ZIP)

VersionRev LevelVersion Notes
08Mar2013 0101
  1. Supports both processor types.

Arbiter Time Service Tool (Arbiter Time Service)

PC Clock Synchronization Service for WIN NT/2000/XP/Vista/7. Not compatible with WIN 8. The Arbiter Time Service installs on Microsoft® Windows NT/2000/XP and runs as a service to keep the PC clock synchronized to an Arbiter GPS clock. The Arbiter Time Service connects with an RS-232 cable and interrogates the clock for the time signal

VersionRev LevelVersion Notes

Terminal Emulation Program (Tera Term)

Free software terminal emulator (communications program) for Microsoft Windows.

  • Tera Term (Pro) is a free software terminal emulator (communication program) for MS-Windows.
  • Supports VT100 emulation, telnet connection, serial port connection, etc.
  • Compatible with Windows 98, Windows NT, Windows 2000, Windows XP, Vista, Windows 7
Firmware Information (EPROM based firmware is not available for download)
1094_Firmware_07Dec2017 Downloadable. Use the 1094 Utility or 109x Loader to import file into unit.


Firmware Version and Related Information

Read the release notes BEFORE downloading any firmware

IMPORTANT: The firmware can only be updated if you have a firmware version of at least 2008. If your version is pre-2008, contact technical support for assistance. See below for instructions how to check your version number.

Firmware Uploader

  • Required to upload the firmware to the Model 1094B.
  • Compatible with Windows NT, 2000 and XP

How do I find my firmware revision?

Using Serial Commands:

  1. Start a terminal program such as TeraTem (available for download on this page)
  2. Configure for 9600, 8, N, 1
  3. Press V
  4. Press E
  5. The terminal program should show the firmware revision date in the format dd mmm yyyy.

Using the 1094GUI utility program (1094utility_vxxxx.exe):

  1. The xxxx refers to the version number of the 1094BGUI Utility
  2. Connect the 1094B to the computer
  3. Run 1094GUI (1094utility_vxxxx.exe)
  4. Click the Version tab
  5. If the data is blank then click Unit > Read

Contact Technical Service if your current firmware is prior to 2008.

Downloadable Firmware (1094_Firmware)

VersionRev LevelVersion Notes

Updates are not security related.

  1. Added support for new processor. This version is backward compatible but old firmware versions are not forward compatible.

Do NOT load older firmware to the new processor. Just don't try it.  Doing so will quickly remove the ability of the 1094B to function properly.


Updates are not security related.

  1. Fixed setting factory defaults. Was not able to perform this function with the previous release.

Updates are not security related.

  1. Minimized the width of IRIG pulses during cold start. This is to make the IRIG-B output undecodeable until locked to three satellites.

Updates are not security related.

  1. Update Daylight Saving Time (DST) function to properly calculate start and stop days.

Updates are not security related.

  1. Update Daylight Saving Time (DST)  pending bit in IRIG-B with IEEE 1344 enabled to start one second into the minute (xx:xx:01) prior to the change.  Before this change the bit was set at the top of the minute, xx:xx:00.
  2. Leap second fixes:
    1. Correctly test for and apply leap seconds
    2. Correctly calculate SBS value at leap second application
    3. Leap-second pending bit in IRIG-B IEEE 1344 output set at proper time and for the proper duration.
  1. Year changeover temporarily changed the IRIG-B time zone. (BZ 735)
  1. DST stop error. Not exiting DST mode properly when "day of week" value matches the first day of the following month (BZ 733). Example: DST will not properly stop if DST stop was set to Last Sunday of October and November 1 is also on a Sunday.
  1. Fixed the lacking leap second.
  2. COM settings cleaned up on the front panel (BZ 731).
  1. Corrected Aux-IRIG-B (Programmable Pulse B - IRIG-B) to properly generate in the new processor.
  1. Supports both processor types.
  2. Add ability to bump the baud rate to maximum when doing a firmware update.
  1. Daylight Saving Time (DST) configuration changes are now loaded without having to cycle power (BZ 688).
  1. Added ability to configure the programmable pulse (seconds per pulse) to 1 second - 1 PPS (BZ 676).
  2. Add Extended Relay Start Feature (BZ 684).
  1. IRIG-B bit position number 70 will now properly change state when the local offset is something other than an even hour (BZ 674).
  1. Update to time quality functionality. Time quality no longer displays locked, maximum accuracy immediately after reacquiring satellites
  1. IRIG-B Time quality bits enabled when 1344 disabled. (BZ 619)
  2. Ability to configure EVENT capture to local/UTC from front panel. (BZ 553)
  3. The SE command's timeout value ("T=x") is always 0. (BZ 605)
  4. Minor menu fix. (BZ 618)
  1. Minor menu fix. (BZ 618)
  1. IRIG-B IEEE 1344 outputs incorrect year (00 instead of 10). (BZ 597)
  1. Number of visible satellites not properly returned using seial commands. (BZ 593)
  1. Update LCD display initialization. Addresses an infrequent, intermittent LCD initialization problem when powered-up from plugging in the power cord (power switch on and plugging in power cord).
  1. Can now configure Event Time (Local or UTC) from front panel. (BZ 569)
  1. Seconds per pulse mode drops setting, greater than 600 seconds, upon power cycle. (BZ 567)
  1. Add NGTS broadcast
  2. Enable TS command to display front panel time when unlocked.
  1. Add check for correct number of parameters to all serial commands that require input parameters.
  2. Add check to make sure the broadcast is active in the broadcast service routine.
  3. Update UART xmit timeout to be based on time instead of count.
  4. Enable use of Xmit FIFO's
  5. Remove TF0 I2C use for timeout (timer wasn't being used)
  6. Fix "Single" programmable trigger mode for channel B
  7. Add new custom broadcast functionality. (BZ 525)
  8. 1344 parity bit fixed. (BZ )
  9. Fix "Relay Fault" output. (BZ 528)
  10. Force NMEA-0183 GLL broadcast to always be UTC time reference. (BZ 531)
  11. Fix "DA" output to correctly show minus sign for deviation values between - 0.01 and - 0.99. (BZ 544)
  12. Backlight setup fix. (BZ 542)
  13. Correct event system (BZ 539 and 540))
  14. Skip rate when setting up event broadcast. (BZ 546)
  15. Events referenced starts from 1 instead of 0
  16. Event buffer size increased to 300 (was 250)
  17. Deviation calculation updated so that it won't be skipped when index pointer is 0.
  18. Add missing keylock functionality
  1. Fix unlock time error. (BZ 509)
  2. Correct event local time calculation for local time offsets greater than + 9 hours and less than - 9 hours. (BZ 516)
  3. Updated IRIG-B code to use index bit for Pr+980ms bit time (Broke in version 02 May 2008). (BZ 518)
  4. Fix slow code programmable pulse output. (BZ 521)
  5. Add Seconds-Per-Pulse functionality to programmable pulse mode. (BZ 522)
  6. Speed-up event format routine: Check for "No Data" moved before time formatting
  7. Broadcast configuration structure cleanup. Remove "," before seconds value in "1DG" broadcast message
  8. Various code cleanup

Add in application firmware update capability. The 1094 can now have its firmware updated by using either of the rear serial ports (doesn't require the interface card).

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) »

NERC PRC-08 Compliance Statement
Download pd0042900a_NERC_PRC-018_compliance_statement.pdf (75 kB) »

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

Why GPS Clocks Are Not Free
Download why_gps_clocks_arent_free.pdf (12 kB) »

App Note 101: Distributing Timing Signals in a High-EMI Environment
Download application_note_101.pdf (90 kB) »

App Note 103: Large Format Displays with Arbiter products
Download application_note_103.pdf (16 kB) »

GPS Antenna Mounting Bracket
Download antenna_mnt_bracket_brief.pdf (462 kB) »

GPS Antenna Mounting Bracket Instructions
Download pd0024700_gps_antenna_mounting_bracket.pdf (580 kB) »

GNSS Antenna Preamplifier Installation Instructions
Download pd0025300_gnss_antenna_preamplifier.pdf (3 MB) »

IRIG Standard 200-16
Download irig-b_200-16.pdf (857 kB) »

IRIG-B Specifications
Download irig_b_spec_brief.pdf (488 kB) »

Chassis Dimensions
Download chassis.pdf (27 kB) »

Clock Option Selection Guide
Download clock_option_selection_guide.pdf (98 kB) »

Clock Selection Guide
Download clock_selection_guide.pdf (120 kB) »

GPS Surge Protector Installation Instructions
Download pd0045800_surge_protector_installation_instructions.pdf (80 kB) »

Reducing Overshoot and Ripple in Arbiter Products with High Drive Outputs
Download pd0046200_reducing_high_drive_overshoot.pdf (277 kB) »

Timing Signals, IRIG-B and Pulses
Download pd0043200_timing_signals_overview.pdf (197 kB) »

Catalogo de Productos de Sincronizacion y Frecuencia
Download catalogo_de_productos_de_sincronizacion_y_frecuencia.pdf (216 kB) »

Press Release: Leap Second Anomaly December 2016
Download PD0054900_LeapSecondPressRelease.pdf (70 kB) »

Model 1094B CE Declaration
Download 1094B_CE_declaration.pdf (287 kB) »

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

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