Rs232C Port Com2 And Com3 Circuit - Casio CE-6800 Service Manual

4-9. RS232C port COM2 and COM3 circuit

The circuits of COM2 and COM3 are as follows:
COM2
The COM2, and COM3 port pin locations are as shown below:
COM2 port
Signal Pin
NC 1
RxD 2
TxD 3
DTR 4
GND 5
DSR 6
RTS 7
CTS 8
VCC (+5V) 9
COM3
COM3 port
Signal Pin
NC 1
RxD 2
TxD 3
1
DTR 4
GND 5
6
DSR 6
RTS 7
CTS 8
NC 9
— 15 —
2 3 4 5
7 8 9
TP48