Twinaxial cabling

[3] Due to cost efficiency it is becoming common in modern (2013) very-short-range high-speed differential signaling applications.

For use in buildings wired with Category 3 or higher twisted pair there are baluns that convert Twinax to twisted pair and hubs that convert from a bus topology to a star topology.

Its main advantages were high speed (1 Mbit/s versus 9600 bit/s) and multiple addressable devices per connection.

The main disadvantage was the requirement for proprietary twinax cabling with bulky screw-shell connectors.

This is like a 1 bit sent at 1/3 normal speed (although the preemphasis pulses remain 250 ns long).

The final frame in a message includes an address of 7 (all ones) as an end-of-message (EOM) indicator.

Direct-Attach Copper (DAC) is a type of standard cabling used in Small Form-factor Pluggable (SFP) Ethernet, initially defined with SFP+ Direct-Attach Copper (10GSFP+Cu), which provides 10 Gigabit Ethernet over either an active or passive twinax cable assembly and connects directly into an SFP+ housing.

An active twinax cable has active electronic components in the SFP+ housing to improve the signal quality; a passive twinax cable is mainly just a straight "wire" and contains few components.

This type of connection is able to transmit at 10 gigabits/second full duplex speed over 5 meter distances.

Twinax copper cabling has a BER of better than 10−18 according to Cisco, and therefore is acceptable for applications in critical environments.

The table on the right summarizes minimum values typically admitted for SFP+ sustained bend radiuses.

The cable used to connect the MIL-STD-1553 bus and stub devices has a characteristic impedance of 78 ohms at 1 MHz.

The two internal dielectric fillers separate the braid from the pairs to minimize the leakage capacitance to ground.