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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. |
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GPS Time Clock
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Specifications |
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Physical Characteristics
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| Box dimensions |
449 x 365 x 90 mm |
| Connectors |
2 U –19 inch Rack mountable systemSMA connector (RF signal input) |
Electrical Characteristics
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| 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
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| 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 |
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| 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.
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| 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.
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| Noise figure |
Less than 2 dB |
| Power supply |
3.3 V |
| Antenna current |
< 20 mA |
Output messages
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| 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.
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| Options |
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The unit can be supplied with a standard interface (IRIGB or Ethernet ) as per customer’s requirement. |
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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. |
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The unit can be supplied with a standard interface (IRIGB or |
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