USGlobalsat EB-5635RE - Manual (Page 9)

2012/7/30 - 9 -
TXD
This is the main transmits channel for
outputting navigation and measurement data
to user’s navigation software or user written
software. Output is TTL level, 0V ~ 2.85V.
RXD
This is the main channel for receiving
software commands from SiRFDemo
software or from your proprietary software.
VBAT
This is the battery backup power input for the
SRAM and RTC when main power is off.
Without the external backup battery, EB-365
will always execute a cold star after turning
on. To achieve the faster start-up offered by
a hot or warm start, a battery backup must be
connected. The battery voltage should be
between 2.0V and 3.5V.
VCC
This is the main power supply to the engine
board. (3.1Vdc to 3.5Vdc)