Appendix D - Pin Descriptions; Rs-232 Pin Descriptions - Multitech MultiModem II MT5600BA-V92 User Manual

Appendix D - Pin Descriptions

RS-232 Pin Descriptions

Label Pin
CGND 1
TD 2
RD 3
RTS 4
CTS 5
DSR 6
GND 7
CFLO 8
+12V 9
10
11
12
13
14
TCLK 15
16
RCLK 17
V54-2 18
19
DTR 20
RDL 21
RI 22
23
XCLK 24
TM 25
Multi-Tech Systems, Inc. MT5600BA-V92 User Guide
I/O Type Signal Name/Description
GND CGND is tied common to GND on the modem's PCB.
Transmitted Data The DTE uses the TD line to send data to the modem for
transmission over the telephone line or to transmit commands to the modem.
Received Data The modem uses the RD line to send data received from the
telephone line to the DTE and to send modem responses to the DTE.
Request to Send The RTS signal is used for hardware flow control.
Clear To Send CTS is controlled by the modem to indicate whether or not the modem
is ready to transmit data. CTS high indicates to the DTE that signals presented on TD
will be transmitted to the telephone line. CTS low indicates to the DTE that it
should not transfer data across the interface on TD.
Out Data Set Ready DSR indicates modem status to the DTE. DSR low indicates that
the DTE is to disregard all signals appearing on the interchange circuits except
Ring Indicator (RI). It reflects the status of the local data set, and does not
indicate an actual link with any remote data equipment.
GND Ground.
CD Carrier Detect The modem uses the CD line to signal to the DTE that a carrier has
been detected.
A positive voltage output from the modem used for tests or for strapping signals
high if needed.
NC
NC
NC
NC
NC
TC Transmit Clock Output from modem, used in synchronous mode.
NC
RC Receive Clock Output from modem, used in synchronous mode.
AL Analog Loop Input to modem to enable analog loop test.
NC
DTR Data Terminal Ready Input to modem from DTE to control answering and
disconnection of modem.
RDL Remote Digital Loop Input to modem to enable RDL test.
Ring Indicator RI output high indicates the presence of a ring signal on the
telephone line.
NC
XCLK External Clock Input to modem used in special synchronous applications.
TM Test Mode Output from modem to indicate modem is in one of the test modes.
Appendix D – Pin Descriptions
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