Specifications

5-11
PA-8T-V.35 Synchronous Serial Port Adapter Installation and Configuration
OL-3563-03
Chapter 5 Configuring the PA-8T-V.35 Interfaces
Configuring the Interface
Setting the Clock Rate
The default operation on a PA-8T-V.35 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
(PA-8T-V.35). 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-8T-V.35 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 later or 11.1(10)CA or later supports nonstandard clock rates (any value
from 1200 to 8000000) on PA-8T-V.35 interfaces installed in Cisco 7204 and Cisco 7206 routers, and
Cisco 7000 series or Cisco 7500 series routers with a VIP.
Cisco IOS Release 11.1(19)CC1 or later or 11.3(4)AA or later supports nonstandard clock rates on
PA-8T-V.35 interfaces installed in Cisco 7202 routers.
Cisco IOS Release 12.0(3)T or later or 12.0(2)XE or later supports nonstandard clock rates on
PA-8T-V.35 interfaces installed in Cisco 7204VXR and Cisco 7206VXR routers.
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
“Inverting the Clock Signal”
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-txc
“Inverting the Clock Signal”
Table 5-4 Clock Rate Configuration Commands (continued)
Purpose Command Example Additional Information