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To configure serial port 0 or 1 in DCE mode to use clock from the baud rate generator, use the clock rate interface configuration command. Use the no form of this command to cancel use of the baud rate generator.
clock rate rate
rate | Desired clock rate in bits per second. The range is 56000 to 2048000. The value entered should be 1000 multiplied by the value set for the network-clock base-rate command. There is no default rate |
No clock rate is configured.
Interface configuration
| Release | Modification |
|---|---|
10.0 | This command was first introduced. |
11.3 MA | This command was modified in to include clock rates for the Cisco MC3810. |
Be aware that the fastest speeds might not work if your cable is too long, and that speeds faster than 148,000 bits per second are too fast for EIA/TIA-232 signaling. It is recommended that you only use the synchronous serial EIA/TIA-232 signal at speeds up to 64,000 bits per second. To permit a faster speed, use EIA/TIA-449 or V.35.
The following example sets the clock on serial port 0 for a clock rate of 64000 bps:
interface serial 0 clock rate 64000
To configure serial port 0 in DTE mode for the incoming line clock rate, use the clock rate line interface configuration command. Use the no form of this command to cancel the clock rate line value.
clock rate line rate
rate | Network clock rate of the incoming line, in bits per second (bps). The value entered must be a multiple of 8000, with a range of 8000 to 2048000. There is no default rate. |
No clock rate is configured.
Interface configuration
| Release | Modification |
|---|---|
11.3 MA | This command was first introduced. |
The value specified with this command must be the clock rate of the incoming line, in bits per second (bps). This allows the appropriate internal clock scaling to be performed, so that the internal clock generator can synchronize to the incoming clock.
The following example configures serial port 0 to recover a clock with a rate of 64000 bps:
interface serial 0 clock rate line 64000
| Command | Description |
network clock select 1 serial 0 | Configures the internal clock generator to synchronize to the clock signal recovered from serial port 0. |
To configure the network clock rate for serial port 0 or 1 in DCE mode, use the clock rate network interface configuration command. The no form of this command cancels the network clock rate value.
clock rate network rate
rate | Network clock rate in bits per second. The range is 56000 to 2048000. The value entered should be a 1000 x multiple of the value set for the network-clock base-rate command. There is no default rate. |
No network clock rate is configured.
Interface configuration
| Release | Modification |
|---|---|
11.3 MA | This command was first introduced. |
This command synchronizes a serial port to the Cisco MC3810 internal clock generator. The use of this command allows the clock on a DCE serial port to be synchronized with any incoming clock.
The following example sets the clock rate on serial port 0 in DCE mode to 64000 bps:
interface serial 0 clock rate network 64000
| Command | Description |
network-clock base-rate | Configures the base rate for serial ports 0 and 1 in DCE mode to operate at a rate compatible with T1 or E1. |
To configure serial interface 0 or 1 to be in clear-channel mode for pass-through traffic, use the encapsulation clear-channel interface command. Use the no form of this command to disable clear-channel encapsulation.
encapsulation clear-channelThis command has no arguments or keywords.
Clear-channel encapsulation is not configured.
Interface configuration
| Release | Modification |
|---|---|
11.3 MA | This command was first introduced. |
When a serial interface is configured for clear-channel encapsulation, it is capable of being cross-connected to the trunk.
The following example configures serial port 0 for clear-channel encapsulation:
interface serial 0 encapsulation clear-channel
| Command | Description |
cross-connect | Configures a connection between a voice dial peer and the FTC trunk. |
To invert the phase of local clock used for timing incoming data on a UIO serial port in DCE mode, use the invert rxclock interface configuration command. To cancel the phase inversion, use the no form of this command.
invert rxclockThis command has no arguments or keywords.
Clock phase is not inverted.
Interface configuration
| Release | Modification |
|---|---|
11.3 MA | This command was first introduced. |
Use this command when received data is phase-shifted due to delay caused by cable length, and the far-end DTE interface does not loop back the transmit clock.
If the far-end DTE interface loops back the transmit clock, use the dce-terminal-timing enable command to synchronize the received data at the DCE interface with the looped-back clock.
The following example inverts the phase of the clock that times received data on serial port 0:
interface serial 0 invert rxclock
| Command | Description |
dce-terminal-timing enable | Prevents phase shifting of received data with respect to clock |
Inverts the phase of the incoming transmit clock on a serial port in DTE mode. |
To invert the phase of incoming transmit clock on a UIO serial port in DTE mode, use the invert txclock interface configuration command. To cancel the phase inversion, use the no form of this command.
invert txclockThis command has no arguments or keywords.
Clock phase is not inverted.
Interface configuration
| Release | Modification |
|---|---|
10.0 | This command was first introduced as invert-transmit-clock. |
11.3 | The command syntax was changed to invert txclock. |
Use this command for a serial port operating in DTE mode if the DTE interface does not loop the transmit clock back, and the data received at the far end is phase-shifted due to delay caused by cable length.
If the a DTE interface loops back the transmit clock, use the dce-terminal-timing enable command at the far-end DCE interface to synchronize the received data at the DCE interface with the looped-back clock, and do not use the invert txclock command.
The following example inverts the phase of the transmit clock on serial port 0:
interface serial 0 invert txclock
| Command | Description |
dce-terminal-timing enable | Prevents phase shifting of received data with respect to clock |
Inverts the phase of local clock used for timing incoming data on a UIO serial port in DCE mode. |
Posted: Mon May 3 15:11:41 PDT 1999
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