
22
DECserver 900GM Installation
Connector Pin Assignments (Cont.)
BN41A-03: 68-pin to Four 25-pin DB Octopus Cable (Optional)
Use this cable on DECserver bulk connectors A through D to provide four
full-modem control connections for each serial port. The following illustration shows
a 68-pin bulk connector to four 25-pin DB connector cable. You can connect the
25-pin DB connectors directly to modems. You must use a crossover adapter or
crossover cable for terminal interconnections. The wire size should be 26 or 28GA,
shielded or unshielded, twisted- or untwisted-pair. On the 68-pin connector, tie pins
67 and 68 together to enable the software to identify the cable. Table 5 lists the
appropriate pin assignments.
NOTE:
You can mix cable BN41A-03 and cable BN41B-03 on serial ports
A through D to create four full modem control connections on one
port and eight partial modem control connections on another.
LKG–4730–93I
12
22
8
7
20
6
5
4
SMI
RI
DCD
DSR
CTS
RTS
DTR
GND
Recommended Wire Pairings for each DB25 Connector
25-pin D-shell Connector
1
2
3
23
SHIELD
RXD
TXD
DSRS
Wires do not need to be
twisted. If they are, they
must be paired as shown
in the diagram.
Pair
Pair
Pair
Pair
Pair
Pair
LKG–09760–94I