Kontron KTH81-mITX - Manual (Page 46)

KTD-N0882-H Page 46 Internal Connectors
KTQ87/KTH81 Users Guide
7.8 Serial COM1 – COM2 Ports (COM1, COM2)
Two RS232 serial ports are available on the KTQ87/KTH81.
The typical definition of the signals in the COM ports is as follows:
Signal Description
TxD
Transmitted Data, sends data to the communications link. The signal is set to the marking state (-
12V) on hardware reset when the transmitter is empty or when loop mode operation is initiated.
RxD Received Data, receives data from the communications link.
DTR
Data Terminal Ready, indicates to the modem etc. that the on-board UART is ready to establish a
communication link.
DSR Data Set Ready, indicates that the modem etc. is ready to establish a communications link.
RTS Request To Send, indicates to the modem etc. that the on-board UART is ready to exchange data.
CTS Clear To Send, indicates that the modem or data set is ready to exchange data.
DCD Data Carrier Detect, indicates that the modem or data set has detected the data carrier.
RI Ring Indicator, indicates that the modem has received a ringing signal from the telephone line.
The pinout of Serial ports COM1 (J19), COM2 (J18)
Note Ioh/Iol Type Signal PIN Signal Type Ioh/Iol Note
- I DCD 1 2 DSR I -
- I RxD 3 4 RTS O
O TxD 5 6 CTS I -
O DTR 7 8 RI I -
- PWR GND 9 10 5V PWR - 1
Note 1: The COM1, COM2 5V supply is fused with common 1.5A resettable fuse.
DB9 adapter cables (PN 821016 200mm long and 821017 100mm long) are available for implementing
standard COM ports on chassis.
Available cable kit (DB9 adapter cables):
PN 821017 - 100 mm or PN 821016 - 200 mm