MVME712M Transition Module
http://www.mcg.mot.com/literature
3-21
3
J20 connector
Connector J20 is the internal modem port. Each pin connection, signal
mnemonic, and signal characteristic for the modem port connector is listed
in the following table.
18-19
Not used.
20
EDTR
DATA TERMINAL READY - A signal from the
terminal to the modem indicating that the terminal is
ready to send or receive data.
21-23
Not used.
24
ETTXC4
TRANSMIT CLOCK (port 4 only) - This line can be
configured to clock output data to the modem from the
terminal.
25
Not used.
Table 3-10. Connector J20 interconnect signals
Pin
Number
Signal
Mnemonic
Signal Name and Description
1
CTS2
CLEAR TO SEND - CTS is a function supplied to
the terminal by the modem, and indicates that it is
permissible to begin transmission of a message.
When using a modem, CTS follows the off-to-on
transition of RTS after a time delay.
2
TXD2
TRANSMIT DATA - data to be transmitted is
furnished on this line to the modem from the
terminal.
3
DCD2
DATA CARRIER DETECT - Sent by the modem to
the terminal to indicate that a valid carrier is being
received.
4
RXD2
RECEIVE DATA - data that is demodulated from
the receive line is presented to the terminal by the
modem.
5-10
Not used.
Table 3-9. Connectors J7 - J10 interconnect signals
Pin
Number
Signal
Mnemonic
Signal Name and Description