Instruction Manual

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GNAV540UserManual
7430‐0808‐01Rev.B
Page35
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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    
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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.