Setting up interface to the ME70/BO Processing Unit
This procedure explains how to connect a GPS system, time and date information, and a motion reference unit to the ME70/BO Processing Unit using serial line communication.
Context
Most Global Positioning System (GPS) receivers provide NMEA 0183 telegrams containing speed, heading and sailed distance as well as geographical latitude and longitude.
The first step in this procedure explains how to do the physical cabling using the relevant connection. The remaining steps describe how to set up the interface parameters in the ME70 software.
Procedure
1 Connect the relevant serial lines to the ME70/BO Processing Unit.
a Locate a free serial port that can be used for this communication.
b On the serial line socket on the ME70 computer, connect an RS-232 cable as follows
•  Receive signal Rx on pin 2.
•  Transmit signal Tx on pin 3.
•  Common Ground on pin 5.
c On the serial line socketon the ME70 computer, connect an RS-232 cable as follows:
•  Receive signal RXD+ on pin 1.
•  Receive signal RXD- on pin 4.
•  Transmit signal TXD+ on pin 2
•  Transmit signal TXD- on pin 3.
•  Common Ground on pin 5.
d On the peripheral system, wire as described in the relevant documentation.
e Ensure that the total length of the serial line cable does not exceed approximately 50 meters.
If a longer cable is required, you may need to use buffer amplifiers on the serial line
2 Setup the interface parameters on the ME70/BO Processing Unit as described in the Seafloor Information System (SIS) documentation.