Specifications

If you experience difficulty in establishing a communications path between your VDT, modems,
and the digital telephone system, note the following suggestions:
•
make sure that you have enabled the modem auto-answer feature,
•
confirm that the modems are wired correctly. Reverse connections at pins 2 and 3 if
necessary,
•
check the modem’s instruction manual. You may have to make additional wiring
connections,
•
sometimes you must strap pin 4 to 5, or pin 6 to 7, or pin 6 to 8 to 20 in the modem wiring.
Check the modem’s installation manual for this requirement,
•
use a breakout box data tester to troubleshoot the data communications lines.
Figure 2–18: Installing a Video Display Terminal
CLIPTERMIINALS
50
26
1
25
{
{
RS232
DATA
PORT A
RS232
DATA
PORT B
TD
RD
CTS
SG
Video Display Terminal Or
Personal Computer
Data Jack
Line
Switch
Telco Network
Network
Jack
Data
Jack
Typical Common
Equipment Cabinet
Data
Port
Line
Port
Network Jack
Data
Modem
Data
Modem
StationConnectorBlock DataPorts
(4-Line,8-StationBase Unit and
8-Line,16-StationBase Unit)
DATACONNECTIONS
SYSTEM
DATAPORT
MODEM
DATAJACK
CTS
RD
TD
SG
--
TD
RD
SG
System requires that the CTS
pinbe at ahighlogiclevel
before it will send data.It will
force the pinhighif no modem
connectionis supplied.
CAJS013
654321
(Front View of Jack)
ModularJack DataPorts
(16-Line,32-StationBase Unit)
1= --
2= CTS
3= RD
4= TD
5= SG
6= --
RS232
DATAPORTS
37
38
39
40
41
42
43
44
45
46
47
48
49
50
TD
RD
CTS
SG
IMI66–107 Digital Telephone System
Installing The DSU 2 – 39