2.4
Checking Signal Paths
To verify correct signal paths between the server and the system, use the following illustration to locate
the signal paths and check them using an ohmmeter.
Be sure that the RD, TD, RTS, and CTS signals from the server connect to the appropriate signals at the
system serial data port as detailed in this table.
Server Signal Connections
System Signal Connections
9-Pin Serial Connector
25-Pin Serial Connector
Modular Serial Data Connector
RDPin 2
RD
Pin 3
TD
Pin 4
TDPin 3
TD
Pin 2
RD
Pin 3
RTSPin 7
RTS
Pin 4
CTS
Pin 2
CTSPin 8
CTS
Pin 5
RTS
Pin 1
6
5
4
3
2
1
6
5
4
3
2
1
6
5
4
3
2
1
6
5
4
3
2
1
2
3
4
5
6
7
20
1
2
3
4
5
6
7
20
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
20
1
2
3
4
5
6
7
20
1
2
3
4
5
6
7
20
1
6
5
4
3
2
1
NC
GND
RD
TD
RTS
CTS
NC
NC
NC
NC
TD
TD
RD
TD
RD
RD
TD
RD
RTS
RTS
DTR
RTS
CTS
CTS
GND
CTS
DSR
DSR
DSR
DSR
GND
GND
RTS
CTS
GND
DTR
DTR
NC
DTR
NC
GND
TD
RD
CTS
RTS
NC
GND
RD
TD
RTS
CTS
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
Jack
Standard
6-Conductor
Line Cord
NOTE: A signal
roll-over occurs in the
standard 6-conductor
line cord. You must
maintain the same
signal roll-over in
the optional house
wiring.
Optional House Wiring
To
DXP
Jack
DXP
Standard
6-Conductor
Line Cord
25-Pin
To Modular
Adapter
Software
Key
9-Pin to
25-Pin Adapter
9-Pin
Connector
25-Pin
Connector
Server
Optional
House
Wiring
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DXP028
Figure 4. Examining The Signal Interconnections
GCA40–121
Installing The Telephone Services Interface
Installing the Telephone Services Interface – 11
