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3000LRS DGPS RECEIVER
OPERATOR’S MANUAL
A Product of the Fugro Group of Companies
Issue 2.00 JUNE 2003
B11203400PMBRA0 / 29
Q-I don’t know if my GPS receiver handles RS232 or RS422. How can I find
out?
A
-In the manual it should state if your input/output ports handle RS232 or RS422.
But you can also deduce that from the pin layout of your input/output ports. Here
are a few clues:
RS232 ports normally only uses 3 wires, labelled Tx, Rx, Gnd or they are labelled
Data out, Data in Gnd.
RS422 ports normally use 4 wires labelled Tx+, Tx-, Rx+, Rx- or they are labelled
Data out+, Data out-, Data in+, Data in-. Note that RS422 does not make use of a
GND (Ground) wire.
Q-How do I connect a RS232/422 converter between the Seastar receiver
and my GPS receiver?
A
-Often it’s the case that GPS receivers using RS422 use different ports to
receive RTCM and transmit NMEA. The port to receive RTCM from the Seastar
receiver is normally a RS232 port; the port to transmit NMEA to the Seastar
receiver could be a RS422 port. Connect the RS232/422 converter as follows:
Seastar
AUX Port
RS232/422
RS232 side
RS422 side
GPS Receiver
Example (port A)
Pin 2-Rx NMEA
Tx-pin 2
+ Data in
Tx + (NMEA)
- Data in
Tx – (NMEA)
Pin 5-Gnd
Gnd-pin 7
Example Port B
Pin 3-Tx RTCM
Rx RTCM
Pin 5-Gnd
GND
*Note: If converter has a switch, ensure that the switch on the RS232/422
converter is set to DTE.