USGlobalsat ER-112 - Manual (Page 6)

ET-112
Specifications are subject to be changed without notice.
Page 6 of 15
Version 1.3
1 VANT Antenna DC Voltage (Input)
2 VDC 3.3~5.5 DC power input (Input)
3 VBAT Backup Battery (Input)
4 VDC (shorted with pin #2)
5 PBRES Push Button Reset Input (Active Low) (Input)
6 ---- (RESERVED)
7 SELECT Download data from RS232 to flash ROM (RESERVED)
8 ---- (RESERVED)
9 ---- (RESERVED)
10 GND Ground
11 TXA
Serial Data Output A (GPS Data)
12 RXA Serial Data Input A(Commands)
13 GND Ground
14 TXB
Serial Data Output B (Not Used)
15 RXB Serial Data Input B (Not Used)
16 GND Ground
17 ---- (RESERVED)
18 GND Ground
19 TIMEMARK 1PPS
Time Mark Output
20 ---- (RESERVED)
Pin Explanation
VANT:
DC Voltage is for an active antenna.
VDC: (DC power input) This is the main DC supply for a 3.3V~5.5V power module board.
VBAT: (Backup Battery) This is the battery backup that powers the SRAM and RTC when main power is
removed. Typical current draw is 10uA. Without an external backup battery or Gold-capacitor, the
module/engine board will execute a cold start after every turn on. To achieve the faster start, a battery or
capacitor should be installed. To maximize battery lifetime, the battery voltage should not exceed the
supply voltage and should be between 2.5v and 3.6V.
PBRES: (Push button reset) This pin provides an active-low reset input to the engine board. It causes the
engine board to reset and start searching for satellites.
SELECT: Do not connect.
TXA: This is the main transmit channel for outputting navigation and measurement data to user’s