With Modem To Transmitters - ASCOM telePROTECT 900 System Installation

System Installation
On Site Paging System
3 km max total length is not exceeded. Each Reference Module and Bus Amplifier has two
FL-bus outputs. The D- and SP/FL-buses must be correctly polarized.
A-bus
Figure 4. System solution: 2-way speech, private lines without modem.
3.3

With Modem to Transmitters

Data and Speech modem introduces delay in the transmitter signal. Transmitter signals "in
the air" will differ and cause distortion in areas of overlapping coverage. A basic rule in
planning an installation is to delay the signals to transmitters equally.
The transmitter code on the D-bus is always generated by the Central Unit. Be sure that
the same number of modem-pairs are used between the Central Unit and each Terminal
transmitter. Several Terminal transmitters can be connected to one Data modem if the
location is suitable.
Synchronize the data modems for the D-bus, see the figure below:
A-bus
SP-bus
D-bus
System bus to
other units
Figure 5. Private lines with Speech Modem.
Speech signals may come from several different units, for example PBX Interface, Receiver
Interface or Control Keyboard. If speech modems are used with any transmitters, the
modem compensator must be used at those terminal sites where speech is fed into the
2006-09-18/ Ver. C
Central PBX Reference
Unit Interface Modul
R-line
to central site FL-bus
D-bus
Reference
Central Data
Module
Unit
Modem Modem
Control
Receiver
e
Interfac
R-line
to terminal site
FL-bus
D-bus
Terminal
Fixed
Transmitter
Receiver
Modem
Data Speech
Modem Compensator
Synchronizing
SP-line
A-line
D-line
Lines via modem
at terminal site
TD 90227GB
Data Data Receiver
Modem
Modem Interface
D-line
R-line
D-bus
FL-bus
Delayed buses
direct to terminal site
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