Interface G703.1 (64 Kbps)
Coding in accordance with G703.1 permits simultaneous transmission of the data of a 64-kHz and an 8-kHz
clock pulse and is carried out according to the following scheme:
•
Division of a 64-kbit period into 4 identical intervals
•
A binary 1 is coded as a block of four 1100
•
A binary 0 is coded as a block of four 1010
•
The binary signal is converted into an AMI-coded signal, with alternating polarity of consecutive blocks of
4. AMI is the abbreviation for Alternate Mark Inversion. The code is generated from the NRZ code by
representing the code elements of the logic 1 state alternately through pulses with positive or negative
voltage.
•
The change of polarity of every eighth block is suppressed for marking the byte (8-kHz clock).
The nominal data rate is 64 Kbps. The bit rate on the line is 256 Kbps due to the conversion of the bits into a
block of 4.
Characteristics:
Number of signal lines:
4 (one balanced pair for transmit and receive direction)
Level, transmitter side:
Space 0 V ± 0.1 V, Mark 1 V
Level, receiver side:
0 dB to 3 dB
Impedance:
120 Ω
Bit rate:
64 Kbps (gross bit rate = 4 x 64 Kbps = 256 Kbps)
Coding:
AMI
9.4
Digital Line Equipment
9.4 Interface G703.1 (64 Kbps)
Smart Communication, SWT 3000 Teleprotection, Equipment Manual
335
C53000-G6040-C605-1, Edition 03.2020
