SBC856A1 Series All-in-One POS Board User’s Manual
22
Jumpers and Connectors
2.4.15 COM PORT Connector: COM1~COM6
The SBC856A1 has six onboard serial ports and have +5V/12V power
on pins 1 and 8 or pin 9, depending on jumper selection. COM1 and
COM2 are standard DB9 connectors. COM3~COM6 are combo
connectors. The pin assignments are listed below:
COM1 COM2
Description
1 1
Data Carrier Detect (DCD)
6 6
Data Set Ready (DSR)
2 2
Receive Data (RXD)
7 7
Request to Send (RTS)
3 3
Transmit Data (TXD)
8 8
Clear to Send (CTS)
4 4
Data Terminal Ready (DTR)
9 9
Ring Indicator (RI)
5 5
Ground (GND)
COM3-COM6 pin assignments;
COM3 COM4
Description
1 1
Data Carrier Detect (DCD)
2 2
Data Set Ready (DSR)
3 3
Receive Data (RXD)
4 4
Request to Send (RTS)
5 5
Transmit Data (TXD)
6 6
Clear to Send (CTS)
7 7
Data Terminal Ready (DTR)
8 8
Ring Indicator (RI)
9 9
Ground (GND)
10 10
N.C.
1
2
