CTC Union ETU01-Plus, Руководство пользователя

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Chapter 1. Introduction
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Clock mode 2 (DTE 1):
In the transparent clocking mode, the ETU01-Plus data channel supplies the
receive clock to the synchronous DCE, and accepts a transmit clock from the DCE
(from the ETC pin). The DCE must transmit data at the rate of the clock signal
supplied by the ETU01-Plus.
Figure 1.3 Transparent Timing
The E1 receive clock provides the clocking source for the user data receive timing
out the RC pin. The user data transmit timing is input from the ETC pin and provides
the clock for the E1 transmit link.
Clock mode 3 (DTE 2):
The ETU01-Plus data channel is physically wired as DCE. 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 DTE2 setting. NOTE: The
X.21 data channel cannot be operated in clock timing mode 3 (DTE2).
Figure 1.4 External Timing
The clock input from the ERC pin provides clocking source for the receive timing,
while clock input from the ETC pin provides the clocking source for the user data
transmit timing and the E1 transmit link.
DCE
Connected
Equipt.
DCE
Data
Port
E1
E1
transceiver
Clock Mode 3: External
Cross-
over
Cable
ETC
ERC
TX
RX
DCE
Connected
Equipt.
DCE
Data
Port
E1
E1
transceiver
Clock Mode 2: Transparent
Cross-
over
Cable
RX
TX
ETC
RC