Specifications

4-9
PA-T3+ Serial Port Adapter Installation and Configuration
OL-3505-03
Chapter 4 Configuring the PA-T3+
Configuring the Interfaces
Setting the Clock Rate
The default operation on a PA-T3+ DCE interface is for the DCE device to generate its own clock signal
(TxC) and send it to the remote DTE. The remote DTE device returns the clock signal to the DCE (the
PA-T3+). Set the clock rate of an interface using the clock rate subcommand, which specifies the clock
rate as a bits-per-second value. This subcommand functions in the same way on all supported platforms.
Before you can assign a clock rate, you must use the interface serial command (followed by the
interface address of the interface) to select the interface to which you want to assign the clock rate value.
In the following example, the clock rate is specified as 72 kbps:
Router(config-if)# clock rate 72000
The preceding command example applies to all systems in which the PA-T3+ is supported. Use the no
clock rate command to remove the clock rate.
Following are the standard clock rates:
1200, 2400, 4800, 9600, 19200 38400, 56000, 64000,
72000, 125000 148000, 250000, 500000, 800000, 1000000,
1300000, 2000000, 4000000, 8000000
When you have finished, 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. Then write the new
configuration to NVRAM using the copy running-config startup-config command.
Note Cisco IOS Release 11.2(7a)P or a later release of 11.2 P, or Release 11.1(10)CA or a later release of 11.1
CA loaded on your Cisco 7200 router or on your Cisco 7000 series or Cisco 7500 series router with a
VIP2-40(=) supports nonstandard clock rates (any value from 1200 to 8000000) on PA-T3+ interfaces.
Cisco IOS Release 12.0(3)T or a later release of 12.0 T, or Release 12.0(1)XE or a later release of 12.0
XE supports nonstandard clock rates on PA-T3+ interfaces installed in Cisco 7204VXR and
Cisco 7206VXR routers.
Cisco IOS Release 11.3(7)NA or a later release of 11.3 NA, or Release 12.0(3)T or a later release of 12.0
T loaded on your Cisco uBR7200 series router supports nonstandard clock rates (any value from 1200
to 8000000) on PA-T3+ interfaces.
Change the clock signal
back to its original phase.
no invert-txc The example sets the transmit clock signal
for a serial interface back to its original
phase.
Router(config)# interface serial 3/0
Router(config-if)# no invert-txc
“Configuring Cyclic
Redundancy Checks”
Invert the data signal. invert data The example inverts the data stream for
both transmit and receive for a serial
interface:
Router(config)# interface serial 3/0
Router(config-if)# invert data
“Configuring Cyclic
Redundancy Checks”
Table 4-4 Clock Rate Configuration Commands (continued)
Purpose Command Example Additional Information