Electrical Specifications; Signal Specifications; Figure 3.1 Trunk Line Loop Start Signalling; Table 3.5 Electrical Characteristics Of The T1 Trunk Line - Samsung OfficeServ 7400 General Description Manual

CHAPTER 3. OfficeServ 7400 Specifications

3.2 Electrical Specifications

3.2.1 Signal Specifications

The signal processing protocol refers to the method of sending signals between the trunk
lines, stations and system, and how status information is provided.
3.2.1.1 Trunk Line Signalling Type
Loop Start
In processing loop start signals, the on-hook and off-hook statuses are controlled by the flow of
electric current. The loop is a closed loop trunk circuit or a standard 2500-type set loop.
T1 Trunk Line
The electrical characteristics of the T1 trunk line comply with the ITU G.703 and G.704
standards.
Transmission speed
Code
Pulse type
Transmission media
Load resistance
Indicated (pulse) nominal peak voltage
Power at the frequency of 772 kHz
Signal
Level
Power at the frequency of 1544 kHz
3-4
OPEN END
GND
T
E
-48 VDC
(C.O.)

Figure 3.1 Trunk Line Loop Start Signalling

Table 3.5 Electrical Characteristics of the T1 Trunk Line

Categories
CLOSED END
T
E
Key Telephone
Specifications
1544 kbit/s ±50 ppm
AMI or B8ZS
Regular square wave: When indicating all valid
signals, comply with the mask (G.703) regard-
less of the codes.
A pair of twisted lines
100 Ω
3.00 V
±12~±19 dBm
25 dB or higher when the power is less than the
power at the frequency of 772 kHz
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