USGlobalsat ER-506 - Manual (Page 5)

ER-506
High Performance GPS Module
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Physical Characteristic
OPERATING Description
GND
This is Ground pin for the baseband circuit.
VIN
This is the main power supply to the engine board. (4.5Vdc to 6.5Vdc)
RXD
This is the main channel for receiving software commands from SiRFdemo software or from your
proprietary software.
TXD
This is the main transmits channel for outputting navigation and measurement data to user’s
navigation software or user written software.
Directive
This pin exports signal to indicate the GPS states.
GPS unfix: always low level.
GPS fixed: one second high level, one second low level.
LED
LED indicator for GPS fix or not fix
LED OFF: Receiver switch off
LED ON: No fixed, Signal searching
LED Flashing: Position Fixed