Model 1084A/B/C GPS Satellite Clock (40 ns)

Value driven version of Model 1088B, featuring the same high accuracy, reliability and many of the same feature-extending options.

Model 1084A/B/C User Manual
Download (3 MB) »

Model 1084A/B/C User Manual Espanol
Download PDF(3 MB) »

Model 1084A/B/C Data Sheet
Download PDF(424 kB) »

Model 1084A/B/C Data Sheet Espanol
Download PDF(443 kB) »

Focused on high performance and maximum value, the Model 1084A/B/C delivers many of the same high end performance, features and flexibility of the 1088B precision time clock, but at lower cost.

Three BNC connectors deliver several output options supporting IRIG-B modulated, and various combinations of IRIG-B unmodulated, Programmable Pulse (supporting multiple output modes) and 1 PPS. All are high drive outputs capable of driving multiple loads wired in parallel.

Like the 1088B but with a single option slot, Model 1084A/B/C supports options for an internal Network Time Protocol (NTP), four configurable fiber optic outputs, COMTRADE Sample Rate Generator, Power System Time, Frequency and Phase Monitor, a second RS-232 port and more.

Model 1084A/B/C is available with three front panel configurations. See Key Features for more information.

Key Features
Specs
Options
Accessories
Software
Firmware
Related Resources

Highest accuracy, < ±40 ns typical; < ±100 ns worst case
Three BNC connectors (optional terminal strip connector available)
Optional Fiber Optic support
NTP compatible
Two Form C (SPDT) fail-safe relays, locked and jumper selectable
Event input support

Versions A/B/C offer various interface options (see photos):

1084A supports four LEDs for monitoring operating status.
1084B adds to the LEDs an LCD display and keypad, providing easy access to setup and system status information.
1084C includes both the operating status LEDs, the LCD display and keypad, and includes a large LED time display.
IEEE C37.118 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	±100 ns rms, 1 PPS output
Typical	< ±40 ns rms, in Position-Hold Mode

Synchronization

CMOS output signals are synchronized to the 1 PPS output, ±50 ns, maximum.
IRIG-B modulated, ±1 µs, maximum
The leading edge of the start bit of a received RS-232 data message may be selected to trigger the Event A input, providing synchronization with 100 ns resolution.

Position Accuracy

10 meters, rms, 90% confidence

Satellite Tracking

Twelve (12) channel, C/A code (1575.42 MHz). Receiver simultaneously tracks up to twelve satellites. Results from all tracked satellites are averaged in Position-Hold Mode or, with Position-Hold Mode off, using least-squares estimation.

Acquisition

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

The GPS Data Backup Battery is included in all Model 1084s. This feature improves acquisition time by supplying constant power to the real-time clock and RAM in the GPS receiver module.

Oscillator

Standard	DCXO, 1x10^-7, unlocked
Allan Variance	(locked to GPS, in Position-Hold Mode) 1 second: 5x10^-10 (2x10^-10, typical) 1 day: 5x10^-13

I/O Configuration

Output Connectors

Three BNC, one IRIG-B Modulated and two user-configurable:

IRIG-B Modulated, bus driver, 4 Vpp, 20 ohms source impedance, drives a 50-ohm load at 3 Vpp
IRIG-B unmodulated or Programmable Pulse; jumper-selectable
1 PPS, IRIG-B unmodulated or IRIG-B modified Manchester; jumper-selectable

Jumper-selectable outputs are 5 V CMOS bus drivers with 10 ohms source impedance and ±75 mA drive capability.

Event Inputs

Event A Input:

One input is available as an alternate function, with a simple hardware modification to the 1 PPS configurable output. The input may be configured to accept an external 1 PPS signal, and measure the deviation from 1 PPS/GPS with 100 ns resolution. Each input may also be configured to record up to 500 sequential events with 100 ns resolution, provided that the events are separated by 11 ms. Event data is stored in battery-backed RAM.

Programmable Pulse Output

Four modes:

Every 1 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

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

Relay Contacts

Two (2) sets, Form C (SPDT) fail-safe, 0.3A at 130 Vdc; one is Locked function; the second one is jumper-selectable and may be Fault, 1 PPH, or Programmable Pulse

Interface

Operator

Display	2 x 20 character supertwist LCD - (Models 1084B/C only) 20 mm (0.8 in.) LED; 9 digits - (Model 1084C only)
Functions	Time: UTC or local Position: latitude, longitude, altitude Receiver and clock status 1 PPS (input) deviation Event time
Status LEDs	Operate (green) On Line (green) Unlocked (red) Fault (red)
Keyboard	Eight keys (Models 1084B/C only)
Setup	Local time offset Output code select: Local/UTC Recorder output A Daylight Saving Time: On/Off/Automatic Backlight control: On/Off/Automatic Event input: Event/1 PPS Programmable Pulse setup Antenna delay Clock offset Out-of-Lock time: 1 to 99 minute(s), Off, or Zero Delay Auto-Survey: On/Off, Survey duration Position Hold: On/Off, Position Auto/Manual Option Configuration and Setup Serial port: RS-232

System

RS-232	1200 to 19,200 baud; 7 or 8 data bits; 1 or 2 stop bits; even/odd/no parity Broadcast modes include ASCII, Extended ASCII, ASCII with Time Quality, and Vorne (output once every second), Status (output onchange of Status) and Event (outputon an Event) Male 9-pin D-sub; Second port available (order number 1084opt19)
RS-422/485	Transmit Only

Power Requirements

Standard

Voltage	85 to 264 Vac, 47 to 440 Hz, 20 VA maximum or 110 to 350 Vdc, 15 W maximum
Inlet	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.

General

Physical

Size	1 RU rack mount or tabletop, 260 mm deep FMS, Rack mounts included. 508 x 381 x 203 mm (20 x 15 x 8 in.), shipping
Weight	2 kg (4.5 lbs), net 5.5 kg (12 lbs), shipping
Antenna	0.75 in. pipe (1 in. - 14 marine) thread Cable Connection: F-type Size: 77.5 dia. x 66.2 mm (3.05 x 2.61 in.) Weight: 170 grams (6.0 oz)
Antenna Cable	Type: RG-6, 15 m (50 ft) provided Weight: 0.69 kg (1.52 lbs) per 15 m
Mounting	0.75 in. pipe (1 in. - 14 marine) thread

Environmental

Temperature	Operating: 0 °C to +50 °C (-20 °C to +70 °C typical) Nonoperating: -40 °C to +75 °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

Except as noted otherwise, only one I/O Option may be installed. Click on the Option of interest for more information.

I/O
1084opt03	Four Additional Configurable Outputs
1084opt06	Parallel BCD Output, 1 ms Resolution
1084opt17	Parallel BCD with Second RS-232 Port
1084opt19 ¹	Second RS-232 Port
1084opt20 ²	Fiber-Optic, Type ST 820 nm
1084opt20A	Four Configurable Fiber-Optic Outputs
1084opt23	COMTRADE Sample Rate Generator
1084opt27	8-Channel High Drive IRIG-B Output
1084opt28	Power System Time, Frequency, and Phase Monitor
1084opt29	Four Additional Outputs with Dry Contact and +25/50 Vdc
1084opt34	Network Time Protocol (NTP) / Precision Time Protocol (PTP) Server
General
1084opt01	LCD Backlight
1084opt04	On/Off Switch (1084A/B/1093A/B)
Power
1084opt07	IEC-320 Power Inlet 85 to 264 Vac RMS, 110 to 370 Vdc
1084opt08	10 to 60 Vdc Terminal Power Strip and Surge Withstand
1084opt10	85 to 250 Vac RMS, 110 to 350 Vdc Terminal Power Strip and Surge Withstand

¹ May be combined with other I/O options that do not include an additional RS-232 port
² May be combined with other I/O options

Included
AS0028200	19 Inch Rack Mount Kit
AS0031000	Operation Manual (1084)
AS0087800	Arbiter Universal GPS Antenna
CA0021315	15 m (50 ft) RG-6 Antenna Cable
P01-P10 ¹	Country specific power cord with straight female end
Available
AP0007700 ²	Modular DB-9 to RJ-11 Adapter, Preconfigured
AP0013400	GPS Antenna Cable Splitter, F-Type, 950-2150 MHz, One Port Pass DC
AS0033100	Rack Slide Kit
AS0044600	GPS Antenna Mounting Kit
AS0044700 ³	21 dB In-Line Pre-amplifier
AS0048900	Antenna Grounding Block Kit
AS0056600	24 Inch Rack Mount Kit
AS0067200 ²	Programming Port Cable with adapter
AS0094500	GPS Surge Protector
CA0019806	RS-232 Null Modem Cable, DB9F-DB9F, 2 m (6 ft) length
CA0021302	2 m (6 ft) RG-6 Antenna Cable
CA0021306	6 m (20 ft) RG-6 Antenna Cable
CA0021330	30 m (100 ft) RG-6 Antenna Cable
CA0021345	45 m (150 ft) RG-6 Antenna Cable
CA0021360	60 m (200 ft) RG-6 Antenna Cable
CA0021375	75 m (250 ft) RG-6 Antenna Cable
CA0022500 ⁴	Option 28 System Frequency Reference Cable, 6 m (20 ft)
CA0023600 ²	RJ-11 Cable Four-Pin Crossed, 2 m (7 ft)
CN0015050 ⁵	50-Pin Parallel BCD Mating Connector
CN0027700	Type F, Male, RG-6 Antenna Cable Crimp-on Connector
CN0027800	Type F, Male, RG-11 Antenna Cable Crimp-on Connector
TF0006000	Type F, RG-11 Antenna Cable Crimp Tool
TF0006400	Type F, RG-6 Antenna Cable Crimp Tool
TF0013200	Antenna Cable Stripping Tool, RG-6
TF0013300	Antenna Cable Stripping Tool, RG-11
WC0004900	300 m (1000 ft) Roll RG-11 Cable
WC0005000	300 m (1000 ft) Roll RG-6 Cable

¹ Only applies if Power Option 07 is ordered
² Used with retired options: Option 32 or Option 33.
³ Used for cable lengths greater than 75m (250ft)
⁴ Used with Option 28.
⁵ Used with Option 06.

Click to Download Latest Version of Software
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.
TimeRC_3.0	NTP Server Test Utility.

Software Version and Related Information

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

Version	Rev Level	Version Notes
01Jan2010	1.5.0.0

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

TimeRC

Used as a test tool for NTP servers, synchronizes computer time over a network.

Version	Rev Level	Version Notes
3.0

Firmware Information (EPROM based firmware is not available for download)
1084_Firmware_20Oct2011	Requires an EPROM update from Arbiter.
Option28_Firmware_05Apr2012	Requires an EPROM update from Arbiter.

Firmware Version and Related Information

EPROM Update (1084_Firmware)

Version	Version Notes
20Oct2011	Event Input: Add legacy support for "xxxA" command response. Can select "Index not active" or "NO DATA" using the new "nRT" command. (BZ 687)
25Aug2011	Fixed Event Input where the start index was not properly set after events were erased. This is related to the new "EN" command that starts the event count at zero or one.
15Aug2011	Added the ability to count events starting from zero (0) or one (1). Controlled by "EN" serial command. Default configuration will be 0.
27Jun2011	Update to time quality functionality. Time quality no longer displays locked, maximum accuracy immediately after reacquiring satellites.
26May2011	Fix IP command buffer and non-response issue. Fix IP address display to use periods (.) instead of colons (:). Fix IR serial command. Was timing out.
12May2011	Add Option 34/35 support. Add "IP" serial command to return Option 34/35 IP addresses. Add display of Option 34/35 MAC addresses Add bit to indicate if unit has ever been locked to GPS. Update NTP status screens.
14Dec2010	Option-28 "PS" command doesn't return correct value. (Reference BZ637) Broadcasting from main and optional serial port problem at 19200 baud. (Reference BZ641)
11Oct2010	Update serial "RD" output to be consistent with 1092/3. (BZ 489) Fix Option 28 XI configuration command. (BZ 490) Will randomly acquire time when powered up with no antenna. (BZ 558) Leap second pending always 0 for Motorola 8-channel receiver. (BZ 632 and 558) NMEA GLL Broadcast needs more detail. (BZ 633)
02Nov2009	Fix power-up set defaults: Incorrectly had to wait until "SETUP" key released. Complete "Position Hold ID" (user or survey position flag) Block user from changing user position or position hold setting while survey active. Add 3D mode qualification for routine that calculates the survey position.

EPROM Update (Option28_Firmware)

Version	Version Notes
05Apr2012	The frequency was unstable off nominal frequency with an error proportional to frequency deviation. Fixed a conversion factor in the calculation. (BZ 692)
13Jul2006	Improved compatibility during transfer of correction values to option 28.

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 (68 kB) »

App Note 102: Synchronizing End-to End Relay Testing with Model 1088B
Download application_note_102.pdf (18 kB) »

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

COMTRADE Sample Rate Generator
Download ds_comt.pdf (27 kB) »

Continual Self Calibration with Power System Time, Frequency and Phase Monitor Option 28
Download power_system_time_freq_phase_monitor_continually_cal.pdf (12 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) »

GPS Antenna Preamplifier Installation Instructions
Download pd0025300a_gps_antenna_preamplifier.pdf (153 kB) »

IRIG Standard 200-04
Download irig-b_200-04.pdf (3 MB) »

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

Internal Network Time Protocol (NTP) Server -DISCONTINUED-
Download ntp.pdf (22 kB) »

Internal Network Time Protocol (NTP) Server Espanol -DISCONTINUED-
Download ntp_option32_espanol.pdf (129 kB) »

Option 32: Internal NTP Server Setup and Operation Guidelines -DISCONTINUED-
Download ntp_option32_english.pdf (279 kB) »

Option 33: Dual Internal NTP Server Setup and Operation Guidelines -DISCONTINUED-
Download ntp_option33_english.pdf (301 kB) »

Option 34: Network Time Protocol (NTP)/Precision Time Protocol (PTP) Server Data Sheet
Download Option34_NTP_PTP.pdf (21 kB) »

Power System Time, Frequency and Phase Monitor
Download power_system_time_freq_phase_monitor.pdf (152 kB) »

Windows^® Time Service Configuration
Download w32time.pdf (14 kB) »

Chassis Dimensions
Download chassis.pdf (27 kB) »

Clock Option Selection Guide
Download clock_option_selection_guide.pdf (20 kB) »

Clock Selection Guide
Download clock_selection_guide.pdf (21 kB) »

Model 1084A/B/C Option List Espanol
Download 1084_optionlist_espanol.pdf (1 MB) »

Timing Products Options and Accessories
Download timing_and_frequency_options.pdf (36 kB) »

Model 1084A/B/C Firmware Upgrade Instructions
Download 1084_DST_ROM_instructions.pdf (646 kB) »

Option 28 Firmware Upgrade Instructions
Download Option28_DST_ROM_instructions.pdf (154 B) »

Option 34: Network Time Protocol (NTP)/Precision Time Protocol (PTP) Server Setup and Operating Guidelines
Download pd0044300_option34.pdf (450 kB) »

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

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