Synchronous devices are identified in the file link.conf by the keyword sync_device, which starts each definition.
Synchronous device definitions have the following general form:
sync_device syncdevn unix_device device_name line_speed line_speed tx_clock txc rx_clock rxc |
Mandatory parameter for synchronous devices. Indicates the start of a synchronous device definition, and assigns a name to the device.
Mandatory parameter for synchronous devices. Identifies the serial port used for synchronous communication, and associates the synchronous device with one of the synchronous paths defined in the file ppp.conf. The value device_name must be the device name of a synchronous serial interface installed in your machine.
For example, device names of the form zshn associate the path with one of the on-board serial interfaces. The device names of the form hihn, associate the path with a high-speed serial interface (HSI).
Mandatory parameter for synchronous devices when internal clocking is selected. The optimum line speed is dependent on the serial device selected. The default value proposed is the optimum line speed for one of the onboard serial interfaces (zsh). Refer to the manufacturer's documentation, if you are using a different serial device.
Mandatory parameter for synchronous devices. Specifies the source of the transmit clock signal. The value txc can be baud (internal clocking using system baud rate), txc (external clocking using the signal on the transmit pin), or rxc (external clocking using the signal on the receive pin). The transmit clock is most commonly set to baud (internal clocking), or txc (external clocking).
Mandatory parameter for synchronous devices. Specifies the source of the receive clock signal. The value rxc can be baud (internal clocking using system baud rate), txc (external clocking using the signal on the transmit pin), or rxc (external clocking using the signal on the receive pin). The receive clock is most commonly set to rxc, for both internal and external clocking.
The following synchronous device definition uses a high-speed serial interface (hih) and external clocking:
sync_device syncdev0 qqunix_devicee hih0 line_speed 0 tx_clock txc rx_clock rxc |
The following synchronous device definition uses one of the onboard serial interfaces (zsh) and internal clocking:
sync_device syncdev0 unix_device zsh0 line_speed 19200 tx_clock baud rx_clock rxc |