Impulse 3612 - Manual (Page 13)

Appendix C - Electrical Interface
Sealevel Systems PC-ACB.MP Page 11
V.35
V.35 is a standard defined by ITU (formerly CCITT) that specifies an electrical, mechanical, and physical interface
that is used extensively by high-speed digital carriers such as AT&T Dataphone Digital Service (DDS). ITU V.35 is
an international standard that is often refereed to as Data Transmission at 48 Kbps Using 60 - 108 KHz Group-Band
Circuits. ITU V.35 electrical characteristics are a combination of unbalanced voltage and balanced current mode
signals. Data and clock signals are balanced current mode circuits. These circuits typically have voltage levels from
0.5 Volts to -0.5 Volts (1 Volt differential). The modem control signals are unbalanced signals and are compatible
with RS-232. The physical connector is a 34-pin connector that supports 24 data, clock and control signals. The
physical connector is defined in the ISO-2593 standard. ITU V.35 specification defines two types of interface
circuits, Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE). The Sealevel Systems
adapter is a DTE interface.