Impulse 5104 - Manual (Page 18)

© Sealevel Systems, Inc. - 16 - ACB-ULTRA.LPCI User Manual
RS-530 / 530A
RS-530 (a.k.a. EIA-530) compatibility means that RS-422 signal levels are met, and the pin-out for the
DB-25 connector is specified. The EIA (Electronic Industry Association) created the RS-530 specification
to detail the pin-out, and define a full set of modem control signals that can be used for regulating flow
control and line status. The major difference between RS-530 and RS-530A lies in some of the modem
control interface signals. In RS-530 the signals all of the modem control signals are differential, in RS-
530A some of these signals are single ended. The RS-530 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.
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 type of interface circuits, Data Terminal
Equipment (DTE) and Data Circuit-Terminating Equipment (DCE). The Sealevel Systems adapter is a
DTE interface.