Avalue Technology ECM-945GSE - Signal Description - Serial Port Connector (COM1, JCOM2, J422;485)

User’s Manual
ECM-945GSE User’s Manual
33
2.4.12.1 Signal Description – Serial Port Connector (COM1, JCOM2, J422/485)
Signal Signal Description
TxD
Serial output. This signal sends serial data to the communication link. The signal is set to
a marking state on hardware reset when the transmitter is empty or when loop mode
operation is initiated.
RxD Serial input. This signal receives serial data from the communication link.
DTR
Data Terminal Ready. This signal indicates to the modem or data set that the on-board
UART is ready to establish a communication link.
DSR
Data Set Ready. This signal indicates that the modem or data set is ready to establish a
communication link.
RTS
Request To Send. This signal indicates to the modem or data set that the on-board
UART is ready to exchange data.
CTS
Clear To Send. This signal indicates that the modem or data set is ready to exchange
data.
DCD
Data Carrier Detect. This signal indicates that the modem or data set has detected the
data carrier.
RI
Ring Indicator. This signal indicates that the modem has received a telephone ringing
signal.