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4. Earlier versions of DualCom GSM were supplied with an E or Earth terminal
next to the PSTN A & B terminals. In this case, connect a 1.0mm earth
cable to Terminal E. Ensure that the other end of this earth cable is con-
nected to a good ground earth. This protects the equipment from high voltages,
e.g. lightning, that may strike the telephone line.
PSTN Line Connection (DualCom ALONE on line)
Your Telecom Service Provider should be asked to supply and fit an analogue
line and an NTP with terminals near the alarm system. The alarm installer
should then follow steps 1 and 2 below. See Fig 9.
Series Connection (DualCom & OTHER EQUIPMENT on line)
Your Telecom Service Provider should be asked to supply and fit an analogue
line and an NTP with terminals near the alarm system. The alarm installer
should then follow steps 1, 2 and 3 below. See Fig 10.
1. Use cable type 1/0.5mm CW1308, feed through the cable entry, connect
the cores to the DualCom terminals marked A and B.
2. Connect the other end of the cable to the Terminal Block connections for the
incoming telephone line, marked A & B, or 2 & 5.
3. If the PSTN line used by DualCom is shared with other customer apparatus
(e.g. telephone, fax or answer machine) connect the terminals marked A1
and B1 on the DualCom to a PSTN Master Socket. The customer may then
plug their phone, fax etc, into that socket.
A PSTN Master Socket type LJU2/4A is suitable and has screw terminals
for connection. These can be obtained from many electrical distributors in-
cluding:
CPC
Part Number: TE 05285
Farnell
Part Number: 916-638 or 101-3290
Maplin
Part Number: FT48C
Rapid
Part Number: 24-0116
RS
Part Number: 472-534
Fig 9
Fig 10