5-16
PA-8T-232 Synchronous Serial Port Adapter Installation and Configuration
OL-3562-03
Chapter 5 Configuring the PA-8T-232 Interfaces
Configuring Half-Duplex and Binary Synchronous Communications in Cisco 7200 Series Routers
waits a user-configured amount of time and then transmits the data. After the transmission, the interface
waits a user-configured amount of time and then deactivates DCD. Constant-carrier mode activates DCD
at all times.
Use the half-duplex controlled-carrier command to configure an EIA/TIA-232 interface for
controlled-carrier mode. Use the no half-duplex controlled-carrier command to return the interface to
constant-carrier mode.
Follow these steps to configure controlled-carrier mode on an EIA/TIA-232 interface:
Step 1
Enter configuration mode and specify that the console terminal is the source of the configuration
subcommands, as follows:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
Step 2
Specify the interface to configure for controlled-carrier mode using the interface serial subcommand
(followed by the interface address of the interface) and then enter the half-duplex controlled-carrier
subcommand.
The following example is for the first interface of the port adapter in port adapter slot 1:
Router(config)# interface
serial 1/0
Router(config-if)# half-duplex controlled-carrier
Step 3
Specify the length of the timer delay the interface uses when it is configured for controlled-carrier mode
by using the following command:
half-duplex timer {cts-delay value | cts-drop-timeout value | dcd-drop-delay value |
dcd-txstart-delay value | rts-drop-delay value | rts-timeout value | transmit-delay value}
where value is the length of the timer delay in milliseconds.
The following example specifies a Data Carrier Detect (DCD) drop delay of 100 milliseconds on the first
interface of a port adapter in port adapter slot 1:
Router(config)# interface
serial 1/0
Router(config-if)# half-duplex timer dcd-drop-delay 100 ms
lists the default delay settings and the value argument for each timer you can use with the
half-duplex timer command.
Table 5-7
Half-Duplex Timer Default Delay Settings
Timer
Command Syntax
Default Settings
1
CTS delay
2
half-duplex timer cts-delay
0
CTS drop timeout
half-duplex timer
cts-drop-timeout
250
DCD drop delay
3
half-duplex timer
dcd-drop-delay
100
DCD transmission start
delay
half-duplex timer
dcd-txstart-delay
100
RTS drop delay
4
half-duplex timer
rts-drop-delay
3
