Electrical Specifications; Signal Specifications; Figure 3.1 Trunk Line Loop Start Signaling; Table 3.9 Electrical Characteristics Of The T1 Trunk Line - Samsung OfficeServ 7200 System Description

3.2 Electrical Specifications

3.2.1 Signal Specifications

The signal processing protocol is used for interfacing messages between the trunk
lines/stations and system. Also, the signal processing protocol refers to the method for
providing status information.
3.2.1.1 Signaling Type of the Trunk Line
Loop Start
When processing the loop start signals, the on-hook and off-hook status is controlled by the flow
of the electric current. The loop is a closed loop trunk circuit or 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.
Transfer speed
Code
Pulse type
Transmission media
Load resistance
Indicated (pulse) nominal peak voltage
Signal Power at the frequency of
Level 772 kHz
Power at the frequency of
1544 kHz
© SAMSUNG Electronics Co., Ltd.
OPEN END
GND
T
E
-48 VDC
(C.O.)

Figure 3.1 Trunk Line Loop Start Signaling

Table 3.9 Electrical Characteristics of the T1 Trunk Line

Category
OfficeServ 7200 System Description
T
E
Specification
1544 Kbits/s ±50 ppm
AMI or B8ZS
Regular square wave: When indicating all valid signals,
comply with the mask (G.703) regardless of the codes.
A pair of twisted lines
100 
3.00 V
±12~19 dBm
25 dB or higher when the power is less than the power
at the frequency of 772 kHz
CLOSED END
X
Key Telephone
3-7