3-22
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Interconnect Signals
3
J21 connector
Connector J21 is the backplane modem power connector. Each pin
connection, signal mnemonic, and signal characteristic for the modem
power connector is listed in the following table.
11
DTR2
DATA TERMINAL READY - A signal from the
terminal to the modem indicating that the terminal is
ready to send or receive data.
12
-12VMODEM
-12 Vdc Power - used by the internal modem.
13
+5VMODEM
+5 Vdc Power - used by the internal modem.
14-15
GND
GROUND
16
+12VMODEM
+12 Vdc Power - used by the internal modem.
17-20
Not used.
Table 3-11. Connector J21 interconnect signals
Pin
Number
Signal
Mnemonic
Signal Name and Description
1
+5VMODEM
+5 Vdc Power - supplied by the backplane and routed
to J20.
2
+12VMODE
M
+12 Vdc Power - supplied by the backplane and routed
to J20.
3
-12VMODEM
-12 Vdc Power - supplied by the backplane and routed
to J20.
4
GND
GROUND
5,6
Not used.
Table 3-10. Connector J20 interconnect signals (Continued)
Pin
Number
Signal
Mnemonic
Signal Name and Description