Furuno FA-150 Operator's Manual page 64

Serial interface I/O circuit
COM1, 2, 3 port
Baud rate selectable from 4800 and 38400 (bps).
RD
TD
GND
COM 4, 5 port
Baud rate selectable from 4800 and 38400 (bps).
RD_2
TD
GND
2.2k.
RD_1
COM6 port
Baud rate selectable from 4800 and 38400 (bps).
2_ RD
TD
GND
2.2k
1_ RD/A D_ DATA
2.2k
AD_CLK
LTC1535C
GND GND 2
LTC1535C
GND GND2
PC400
LTC1535C
GND2
PC400
W
PC400
W
110.
COM1_ JP
COM1_ JP
COM1_ RD_ B
COM1_ RD_ A
COM1_ TD_ B
COM1_ TD_ A
GND_ ISO
110.
COM4_JP
COM4_JP
COM4_2_RD_B
COM4_2_RD_A
COM4_TD_B
COM4_TD_A
GND_ISO
470.
COM4_1_RD_H
COM4_1_RD_C
110.
470.
220.
220.
APPENDIX
COM6_JP
COM6_JP
COM6_2_RD_B
COM6_2_RD_A
COM6_TD_B
COM6_TD_A
GND_ISO
COM6_1_RD_H
AD_DATA_H
COM6_1_RD_C/AD_DATA_C
AD_CLK_H
AD_CLK_C
AP-7