T-GPS User Manual Version 1.2 | 29
5.
Working Principle
Pulse A
IRIG-B AC
DCF77
IRIG-B DC
RS232
RS422
Pulse
Circuit
GPS
Receiver
Pulse B
Pulse D
Pulse C
Programmable
Pulse
BUS
CPU
LED&
Keyboard
Control/Setup
and Watchdog
IRIG-B
Coder
Antenna
Figure 5.1: Schematic of T-GPS3000A
i.
GPS Receiver
This receiver is the module used to receive Satellite signals, it outputs a pulse at 1 PPS to an
accuracy of 1 µS, and provide UTC time, date and the precise location.
ii.
Pulse Generation Circuit
This outputs a pulse per second (1 PPS), per minute (1PPM), or per hour (1 PPH). The pulse can
be TTL, a wet contact or a dry contact.
iii.
Central processing Unit
The CPU monitors the whole system, receives satellites signals, correlates, displays local time
through the front-panel LED, and also controls the output port status.
iv.
RS-232/422/485 Port
The RS-232/422/485 port outputs the local time, date and position with optional baud rate
v.
IRIG-B Port
The IRIG-B port outputs sine modulated signals and DC demodulated signals.
