Chapter 8
Serial-Port Interfaces
Kontron User's Guide PC/104-520
19
8.
Serial-Port Interfaces
Two fully functional serial ports (COMA and COMB) provide asynchronous serial communications. COMA and
COMB support RS-232 operation modes. They are 16550 high-speed UART compatible and support 16-byte
FIFO buffers for transfer rates from 50 Baud to 115.2 KBaud.
8.1
Connector
COMA is available through the J1 connector (10 pins) and COMB through the J2 connector (10 pins). To
have the signals available on the standard serial interface connectors DSUB-9 or DSUB-25, an adapter cable
is required.
A 9-pin DSUB cable is available from Kontron (KAB-DSUB9-2, Part Number 96017-0000-00-0). The fol-
lowing table shows the pinouts for COMA and COMB, as well as necessary connections for DSUB adapters.
Header
Pin Signal Name
Function
In/Out
DSUB-25
DSUB-9
1
/DCD
Data Carrier Detect
In
8
1
2
/DSR
Data Set Ready
In
6
6
3
RxD
Receive Data
In
3
2
4
/RTS
Request to Send
Out
4
7
5
TxD
Transmit Data
Out
2
3
6
/CTS
Clear to Send
In
5
8
7
/DTR
Data Terminal Ready
Out
20
4
8
/RI
Ring Indicator
In
22
9
9
GND
Signal Ground
--
7
5
10
VCC
(1)
+5V
--
--
--
Note:
1
To protect the external power lines of peripheral devices, make sure that
- the wires have the right diameter to withstand the maximum available current.
- to enclosure of the peripheral device fulfills the fire-protecting conditions of IEC/EN 60950.
To find the location of the serial ports on the PC/104-520 board, please see the Appendix “Connector Lay-
out”.
