E&M (earth & magneto, or ear & mouth) to E1 G.703 converter provides conversion between ITU-T G.703 standard E1 framed interface and 1 to 8 E&M ports

Features

• Realizes long-distance monitoring of local device to the remote device based on self-copyright IC;
• Provides two clock types: E1 master clock, E1 line clock;
• Provides loop-return function, namely E1 self-looping at local end, realize the automatically rate set of local device to remote device
• Has the function of pseudo-random code testing, convenient for opening of the circuit, and can be used as an error code instrument;
• E1 supports 75Ω unbalanced and 120Ω balanced impedance at the same time;
• Provides 1-8*4 wire E&M channels, support calling indiaction
• Voice port supports 4wire E&M;

Specification

E1 interface
Interface standard：Conforms to G.703 standard
Interface rate：2048K
Code：HDB3
Interface impedance：75Ω (unbalanced), 120Ω (balanced)
Connecter：BNC (75 Ω), RJ45 (120 Ω)
Vibration characteristic：Satisfies G.742 and G.823 standard
Clock type：internal-clock, line clock

E wire
Max current：22mA
Saturation voltage：3V
Dial speed：>20pps

M wire
steady current：7 mA
min test current：5 mA
pluse dial recognition：>20pps

Physical Dimension :19inch rackmout
483（L）× 140（W）× 50（H）mm

Operation Condition
Voltage：AC180V ~ 240V；DC –48V；DC +24V
Consumption：≤5W
Operating temperature：0°C~50°C
Storing temperature：-40°C~+70°C
Relative humidity：95 %
Without disturbance of erosive and solvent gas, raising dust or strong magnetic field

Description

E&M (earth & magneto, or ear & mouth) to E1 G.703 converter provides conversion between ITU-T G.703 standard E1 framed interface and 1 to 8 E&M ports.

The E&M standards were initially developed by Bell Labs and extended by national PTT administrations. The standard defines two sides to the interface:

• Trunk Circuit – this is normally the PABX
• Signaling Unit – this used to refer to the special modem that converted the DC signaling systems into tones that could be transmitted over a 4-wire link back to the PTT exchange.

The Signaling Unit and Trunk Circuit communicate their status over the E and M leads, using a combination of Battery and Earth (also known as Ground). The Battery signal used in the standard is nominally -48VDC. All E&M installations require that the +ve terminal of the Battery is connected to a shared reliable Earth.

The maximum distance between the Signaling Unit and the Trunk interface is determined by the resistance of the wire, but will normally be less than 100m for adequate noise immunity.

Additional Information