Specifications

4-8
PA-T3+ Serial Port Adapter Installation and Configuration
OL-3505-03
Chapter 4 Configuring the PA-T3+
Configuring the Interfaces
Step 5 Reenable the interfaces using the no shutdown command. (See the “Shutting Down an Interface” section
on page 4-2.)
Step 6 Configure all additional port adapter interfaces as required.
Step 7 After including all of the configuration subcommands to complete your configuration, press
Ctrl-Z—hold down the Control key while you press Z—or enter end or exit to exit configuration mode
and return to the EXEC command interpreter prompt.
Step 8 Write the new configuration to NVRAM as follows:
Router# copy running-config startup-config
[OK]
Router#
This completes the procedure for creating a basic configuration.
Configuring Timing (Clock) Signals
All EIA/TIA-232 interfaces support both DTE and DCE mode, depending on the mode of the compact
serial cable attached to the port. To use a port as a DTE interface, you need only connect a DTE compact
serial cable to the port. When the system detects the DTE mode cable, it automatically uses the external
timing signal. To use a port in DCE mode, you must connect a DCE compact serial cable and set the
clock speed with the clock rate configuration command. You must also set the clock rate to perform a
loopback test. This section describes how to set the clock rate on a DCE port and, if necessary, how to
invert the clock to correct a phase shift between the data and clock signals. Table 4-4 summarizes some
of the commands used to configure the clock rate. See the specific sections that follow for further details.
Table 4-4 Clock Rate Configuration Commands
Purpose Command Example Additional Information
Set standard clock rate. clock rate The example is for a serial interface with a
standard clock rate of 72 kbps.
Router(config)# interface serial 3/0
Router(config-if)# clock rate 7200
“Configuring Cyclic
Redundancy Checks”
Set nonstandard clock
rate.
clock rate The example is for a serial interface with a
nonstandard clock rate of 1234567 kbps.
Router(config)# interface serial 3/0
Router(config-if)# clock rate 1234567
“Configuring Cyclic
Redundancy Checks”
Remove a clock rate that
has been set.
no clock rate The example is for a serial interface and
removes a standard clock rate of 72 kbps.
Router(config)# interface serial 3/0
Router(config-if)# clock rate 7200
Router(config-if)# no clock rate
“Configuring Cyclic
Redundancy Checks”
Invert the transmit clock
signal.
invert-txc The example inverts the transmit clock
signal for a serial interface.
Router(config)# interface serial 3/0
Router(config-if)# invert-txc
“Configuring Cyclic
Redundancy Checks”