Syntax
Asynchronous serial interface:
detect dsr-dtr
undo detect dsr-dtr
Synchronous serial interface:
detect { dcd | dsr-dtr }
undo detect { dcd | dsr-dtr }
Default
Data carrier and level detection is enabled on serial interfaces.
Views
Synchronous serial interface view, asynchronous serial interface view
Default command level
2: System level
Parameters
dsr-dtr: Detects the data set ready (DSR) and data terminal ready (DTR) signals of the DSU/CSU.
dcd: Detects the data carrier detect (DCD) signal of the DSU/CSU on the serial interface.
Usage guidelines
If level detection is disabled on an asynchronous serial interface, the system automatically reports that the
state of the serial interface is up with both DTR and DSR being up without detecting whether a cable is
connected. If level detection is enabled on the interface, the system detects the DSR signal in addition to
the external cable. The interface is regarded as up only when the detected DSR signal is valid. Otherwise,
it is regarded down.
By default, the system places a synchronous serial interface in up state only when it detects the correct
DSR signal, DCD signal, and cable connection. The system shuts down the interface if it fails to detect any
of these items. If level detection is disabled, the system places the interface, DTR, and DSR in up state
when it detects a cable connection.
Examples
# Enable data carrier detection on synchronous serial interface 2/0.
<Sysname> system-view
[Sysname] interface serial 2/0
[Sysname-Serial2/0] detect dcd
display interface analogmodem
Use display interface analogmodem to display information about an AM interface.
Syntax
display interface [ analogmodem ] [ brief [ down | description ] ] [ | { begin | exclude | include }
regular-expression ]
display interface analogmodem interface-number [ brief [ description ] ] [ | { begin | exclude | include }
regular-expression ]
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