Table C-1. Eia-232-D Interconnect Signals - Motorola MVME2700 Series Installation And Use Manual

Pin
Number
1
2
3
4
5
6
7
8
9-14
15
16
17
18, 19
20
21
22
23
24
25
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Table C-1. EIA-232-D Interconnect Signals

Signal
Mnemonic
Not used.
TxD Transmit Data. Data to be transmitted; input to modem from terminal.
Receive Data. Data which is demodulated from the receive line;
RxD
output from modem to terminal.
Request To Send. Input to modem from terminal when required
to transmit a message. With RTS off, the modem carrier remains
RTS
off. When RTS is turned on, the modem immediately turns on the
carrier.
Clear To Send. Output from modem to terminal to indicate that
message transmission can begin. When a modem is used, CTS
CTS
follows the off-to-on transition of RTS after a time delay.
Data Set Ready. Output from modem to terminal to indicate that
DSR
the modem is ready to send or receive data.
SG Signal Ground. Common return line for all signals at the modem
interface.
Data Carrier Detect. Output from modem to terminal to indicate
DCD
that a valid carrier is being received.
Not used.
Transmit Clock (DCE). Output from modem to terminal; clocks
TxC
data from the terminal to the modem.
Not used.
Receive Clock. Output from terminal to modem; clocks input
RxC
data from the terminal to the modem.
Not used.
Data Terminal Ready. Input to modem from terminal; indicates
DTR
that the terminal is ready to send or receive data.
Not used.
Ring Indicator. Output from modem to terminal; indicates that an
incoming call is present. The terminal causes the modem to
RI
answer the phone by carrying DTR true while RI is active.
Not used.
Transmit Clock (DTE). Input to modem from terminal; same
TxC
function as TxC on pin 15.
Busy. Input to modem from terminal; a positive EIA signal
applied to this pin causes the modem to go off-hook and make the
BSY
associated phone busy.
Serial Interconnections
Signal Name and Description
C
C-3