3Com 3C13701, Руководство по установке

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16 C
HAPTER
2: I
NTRODUCING
R
OUTER
5012 SIC
S
The baud rate cannot exceed 64 kbps if the V.24 cable is used and the interface
operates in synchronous mode.
Introduction to DTE and
DCE
The synchronous serial port supports both data terminal equipment (DTE) and
data circuit-terminating equipment (DCE) operating modes. If two devices are
directly connected and one operates in the DTE mode, the other will operate in
the DCE mode. The DCE device provides the synchronous clock and specifies the
communication rate. The DTE device receives the synchronous clock and
communicates at the specified rate. Generally, the router is used as a DTE device.
To make sure that the device is a DTE or DCE, refer to the manual shipped with
this device. Table 14 provides additional information to help you identify the type
of the device.
An asynchronous serial port is generally used as dialing port and is connected to a
modem or a terminal adapter (TA). In this case, regardless of the operating mode
of the device, you need to select only the appropriate baud rate for the port.
Figure 12 illustrates the 1-Port Serial SIC.
Figure 12 1-Port Serial SIC
64000 20 56000 60
115200 10 64000 50
- - 2048000 30
Table 13 Baud Rate and Transmission Distance of V.24 (EIA/TIA-232)/V.35 Cable
V.24 (EIA/TIA-232) V.35
Baud Rate (bps)
Maximum
Transmission
Distance (m)
Baud Rate (bps)
Maximum
Transmission
Distance (m)
Table 14 Typical DTE and DCE Equipment
Equipment type Interface type Typical equipment
DTE male PC, router
DCE female modem, multiplexer,
CSU/DSU