Interface G703.6 (2 Mbps Hdb3) - Siemens SWT 3000 Equipment Manual

Digital Line Equipment

9.5 Interface G703.6 (2 Mbps HDB3)

9.5 Interface G703.6 (2 Mbps HDB3)
Coding in accordance with G.703.6 is also known as HDB3-code (High Density Bipolar of order 3). Longer
sequences of zeros, such as can occur with the AMI code are avoided here. If there are 4 consecutive binary
zeros, the infringement of the AMI coding regulation changes the fourth character. This means that a
maximum of 3 consecutive binary values of 0 can occur with the HDB3 code. The polarity of the changed code
elements alternates. The HDB3 code is one of the voltage-free codes.
NOTE
i
i
It is possible to select between a balanced line (120 Ω) and an unbalanced line (75 Ω, connected to GND
potential). The line impedances are set with links.
Characteristics:
Balanced line Number of signal
Unbalanced
line
336
4 (one balanced pair each for transmit and receive direction)
lines:
Level, transmitter Space 0 V ± 0.1 V, Mark 1 V
side:
Level, receiver side: Loss at 1024 kHz 0 dB to 6 dB
Impedance: 120 Ω
Number of signal 4 (one unbalanced line each for transmit and receive direction)
lines:
Level, transmitter Space 0 V ± 0.237 V, Mark 2.37 V
side:
Level, receiver side: Loss at 1024 kHz 0 dB to 6 dB
Impedance: 75 Ω
Line lengths: short = indoor, long = outdoor
Bit rate: 2 Mbps
Coding: HDB3
Smart Communication, SWT 3000 Teleprotection, Equipment Manual
C53000-G6040-C605-1, Edition 03.2020