GPS disciplined Clock, is a precise timing unit, which displays and also outputs GPS synchronized accurate time and date. The unit provides input /output connectors / ports for the reception / generation of appropriate timing signals for a variety of system requirements. In the absence of GPS signal, the GPS Clock switches to hold over mode, which ensures system synchronization for extended hours with reduced accuracy. The unit generates 1 PPS signal from an internal high
stability clock and synchronizes with the 1 PPS signal output from GPS Receiver. The Unit is specifically designed to meet the requirements of timing and synchronization applications. On power ON, the unit starts acquiring GPS Satellites, computes user position, time and outputs 1 PPS signal with time messages through rear panel connectors. A Selector switch provided in the front panel allows the user to select GPS/UTC/IST for display of time. The unit has provision for
outputting the GPS messages through RS232 port, which can be monitored on Accord’s GVISION User Interface software running on a PC. A separate one PPS signal from GPS is also available on a BNC connector in TTL format. The unit is designed to operate either from AC mains or DC supply and has a lockable switch for preventing accidental switching off of the unit. The unit is designed to meet the environmental standards and safety regulations.

GPS Time Clock


     
Specifications

 

 

Physical Characteristics
Box dimensions 449 x 365 x 90 mm
Connectors
2 U –19 inch Rack mountable systemSMA connector (RF signal input)
Electrical Characteristics
Power Supply Voltage
28 V DC Nominal or
Provision to operate from AC mains.
Power consumption
230 Volts, 100 milli amps or 15 Wpeak on DC mode.
EMI/EMC Filters
The unit has a built in Feed through Filter and provides protection against EMI and EMC interferences.
Receiver Characteristics
Performance Characteristics
Receiver
12 channel L1-C/A code SPS Continuous Tracking Receiver
Time update rate 1 sample per second
Environmental Characteristics
Operational temperature range (ambient) 0oC to +55oC – Commercial grade
Storage temperature range -20o C to + 65o C
Humidity 95% non condensing
Altitude 18,000 meters
PC / Host Communication
Interface RS232 Compatible / RS 422Compatible
Baud rate 9600
Message formats Proprietary ASCII / Binary
Start bits / Stop bits 1
Data bits 8
Parity check /Flow control None
   
 
1 PPS (Pulse Per Second)
Pulse width 5 milliseconds
Level TTL compatible
Rise time 10 nanoseconds
Synchronization
Rising edge synchronized to GPS time within +/- 100-nano second accuracy.
Accuracy +/- 100 nanoseconds (typical)
Active antenna
Gain requirement
16 dB after cable loss –Suitable cable to get the required power (Low loss cable) at the Antenna connector may be selected for reliable operation.
Noise figure Less than 2 dB
Power supply 3.3 V
Antenna current < 20 mA
Output messages
NMEA (available on GPS data connector)
$GPGGA, $GPGSA, $GPRMC, $GPGLL, $GPGSV, $GPVTG, $GPZDA
TIME and POSITION
Message in Binary form, with Figure of merit (Available on 4 nos.of D-type connectors, designated as DIFF-1 to DIFF-4)-Differential output along with 1 PPS output.
Options
 
The unit can be supplied with a standard interface (IRIGB or Ethernet ) as per customer’s requirement.
 
The unit can be supplied with OCXO or Rubidium reference oscillator depending on the requirement of timing accuracy during hold over duration for the specific application.
  The unit can be supplied with a standard interface (IRIGB or
 
   Copyrights © 2005 ACCORD Software & Systems Pvt. Ltd. GPS Smartworks Downloads