Moog Crossbow GNAV540 - Manual (Page 35)

GNAV540 User Manual
7430‐0808‐01 Rev. B Page 35
Chapter 3. Hardware Interface
This chapter provides information about the power and signal interface connectors.
J1—I/O Connector
NOTE: Signals labeled as NC have internal pull‐up mechanisms. To ensure proper operation of the unit, ensure there
are no connections to these pins.
Table 11 I/O Connector
Pin No. Signal Pin No. Signal
1 Signal Ground 20 NC
2 Chassis Ground 21 Master_BIT_CONN
3 User RS‐422 Tx (+) 22 NC
4 User RS‐422 Tx (‐) 23 USER_PORT_SEL_CONN
5 User RS‐422 Rx (+) 24 NC
6 User RS‐422 Rx (‐) 25 EXT‐PPS‐INPUT‐CONN
7 NC 26 GPS RS422 TX(+)
8 NC 27 GPS‐PPS‐OUT_CONN
9 10/100 Base Tx(+) 28 MAG RS422 RX(‐)
10 10/100 Base Tx(‐) 29 MAG RS422TX(+)
11 GPS RS422‐Rx(+) 30 MAG RS422TX(‐)
12 GPS RS422‐Rx(‐) 31 Signal Ground
13 10/100 Base Rx(+) 32 Signal Ground
14 Mag RS422 Rx(+) 33 NC
15 Mag RS422 Rx(+) 34 GPS RS422 TX(‐)
16 10/100 Base Rx(‐) 35 MAG RS422 RX(‐)
17 Input Power (+Vin) 36 NC
18 Input Power (+Vin) 37 BOOT_SEL_CONN
19 Signal ground
J2—GPS Antenna Connector
The GPS receiver needs to receive signals from as many satellites as possible. A GPS receiver does not work properly
in narrow streets and underground parking lots or if objects or human beings cover the antenna. Poor visibility may
result in position drift or a prolonged Time‐To‐First‐Fix (TTFF). A good sky visibility is therefore a prerequisite.
Even the best receiver can’t make up for signal loss due to a poor antenna, in‐band jamming or a poor RF cable.
The unit ships with an external active antenna that must be connected properly to SMA jack on the unit case. Placing
the antenna on a 16 square inch or larger ground plane is highly recommended.