Specifications

4-7
Catalyst 4224 Access Gateway Switch Software Configuration Guide
OL-2031-02
Chapter 4 Configuring the Data Interfaces
Configuring Asynchronous/Synchronous Serial Interfaces
Step 4
Enter the interface configuration mode.
You know you have entered interface configuration mode
when the prompt changes to
gateway(config-if)#.
gateway(config)# interface
serial 1/0
gateway(config-if)#
Step 5
Assign the IP address and subnet mask to the interface.
Note All serial ports are initially configured as
synchronous.
gateway(config-if)# ip
address 172.16.74.1
255.255.255.0
Step 6
To use a port in Data Communication Equipment (DCE)
mode, connect a DCE cable and set the internal transmit
clock signal (TXC) speed in bits per second. (For ports used
in Data Terminal Equipment (DTE) mode, the
Catalyst 4224 automatically uses the external timing
signal.)
gateway(config-if)# clock
rate 7200
Step 7
When a port is operating in DCE mode, the default
operation is for the DCE to send serial clock transmit (SCT)
and serial clock receive (SCR) clock signals to the DTE, and
for the DTE to return an serial clock transmit external
(SCTE) signal to the DCE.
If the DTE does not return an SCTE signal, enter this
command to configure the DCE port to use its own clock
signal.
gateway(config-if)#
dce-terminal-timing-enable
Step 8
A Catalyst 4224 that uses long cables might experience high
error rates when operating at higher transmission speeds,
because the clock and data signals can shift out of phase.
If a DCE port is reporting a high number of error packets,
you can often correct the shift by inverting the clock using
this command.
gateway(config-if)#
invert-txcclock
Step 9
All serial interfaces support both nonreturn to zero (NRZ)
and nonreturn to zero inverted (NRZI) formats. NRZ is the
default; NRZI is commonly used with EIA/TIA-232
connections in IBM environments. To enable NRZI
encoding on an interface, enter this command.
gateway(config-if)#
nrzi-encoding
Task Command