HP MSR2000/3000/4000 Router Series Interface Command Reference

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Default
Level detection is enabled on a serial interface.
Views
Synchronous serial interface view, asynchronous interface view, synchronous/asynchronous interface
view
Predefined user roles
network-admin
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 DCD on synchronous serial interface Serial 2/0.
<Sysname> system-view
[Sysname] interface serial 2/0
[Sysname-Serial2/0] detect dsr-dtr
# Enable DCD on asynchronous serial interface Async 6/4/0.
<Sysname> system-view
[Sysname] interface async 6/4/0
[Sysname-Async6/4/0] detect dsr-dtr
Related commands
detect dcd
display interface async
Use display interface async to display information about an asynchronous interface.
Syntax
display interface [ async ] [ brief [ down | description ] ]
display interface [ async [ interface-number ] ] [ brief [ description ] ]
Views
Any view
Predefined user roles
network-admin
network-operator