CTC Union ETU01-Plus, User Manual

Page: 14 / 44

Chapter 1. Introduction
14
Clock mode 4 (DTE 3):
The ETU01-Plus data channel is physically wired as DCE (classed as
communication equipment). However, the ETU01-Plus may operate as a DTE when
connected to other DCE equipment by using a cross-over data cable and by setting
the clock mode to the DTE3 setting. The ETU01-Plus data channel then operates as
a DTE and accepts both transmit clock and receive clock (both from the ETC pin)
from the user equipment.
Figure 1.5 External Timing
The clock input from the ETC pin provides both clocking sources for the receive
timing and for the user data transmit timing as well as clock for the E1 transmit link.
1.6 Functional Description
The ETU01-Plus is a single port access unit for E1 or Fractional E1 service. The
ETU01U-Plus is a single port access unit for Unframed E1 only. The ETU01-Plus AC
model has a universal, auto-switching power supply (90~250VAC) while the DC
model's internal regulator module accepts DC voltages from 18 to 75 volts.
The ETU01-Plus data channel supports user-selectable transmission rates, which
are integer multiples of 56 or 64kbps, up to a maximum 2.048Mbps, for a line
attenuation of up to 43 dB on twisted pair or coax cable. This provides an
approximate operating range up to 2km (22AWG). (The ETU01U-Plus data interface
supports a full 2.048Mbps unframed rate ONLY.)
The ETU01-Plus packs the data channel into E1 link time slots in user-selected
time slots. The unused time slots can insert IDLE code (In frame mode) or insert the
receive side time slots data (In cascade mode). (The ETU01U-Plus only supports
unframed mode and transparently uses the entire E1 bandwidth.)
The ETU01-Plus fully meets all of the E1 specifications including ITU-T G.703,
G.704, G.706, G.732, and G.823.
DCE
Connected
Equipt.
DCE
Data
Port
E1
E1
transceiver
Clock Mode 4: External
Cross-
over
Cable
ETC
TX
RX