3Com MSR 30, MSR 50 manual Eliminate-pulse, Syntax eliminate-pulse Undo eliminate-pulse

194CHAPTER 11: FUNDAMENTAL SERIAL INTERFACE CONFIGURATION COMMANDS

Parameter dsr-dtr: Detects DSR (data set ready) and DTR (data terminal ready) signals of DSU/CSU (data service unit/channel service unit).

dcd: Detects the DCD (data carrier detect) signal of the DSU/CSU on the serial interface.

Description Use the detect command to enable data carrier detection as well as level detection on the serial interface.

Use the undo detect command to disable data carrier detection as well as level detection on the serial interface.

By default, data carrier and level detection is enabled on serial interfaces.

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 up only when the detected DSR signal is valid. Otherwise, it is regarded down.

When determining whether a synchronous serial interface is up or down, the system by default detects the DSR signal, DCD signal, and presence of cable connection. Only when the three signals are all valid will the interface be regarded up. If level detection is disabled, the system considers that the interface is up with both DTR and DSR being up after detecting the cable connection.

n Theexclusive.modem command and the undo detect dsr-dtrcommand are mutually

Example # Enable data carrier detection on synchronous serial interface 2/0.

<Sysname> system-view

[Sysname] interface serial 2/0

[Sysname-Serial1/0] detect dcd

eliminate-pulse

Syntax eliminate-pulse

undo eliminate-pulse

View Asynchronous serial interface view

Parameter None

Description Use the eliminate-pulsecommand to eliminate the pulses with a width less than 3.472 us, thus increasing signal reliability. This is useful when the line is seriously interfered.