PCL(4)

NAME
pcl - DEC CSS PCL-11 B Network Interface

SYNOPSIS
device pcl0 at uba? csr 164200 vector pclxint pclrint

DESCRIPTION
The pcl device provides an IP-only interface to the DEC CSS PCL-11 time division multiplexed network bus. The controller itself is not accessible to users.

The hosts's address is specified with the SIOCSIFADDR ioctl(2). The interface will not transmit or receive any data before its address is defined.

As the PCL-11 hardware is only capable of having 15 interfaces per network, a single-byte host-on-network number is used, with range [1..15] to match the TDM bus addresses of the interfaces.

The interface currently only supports the Internet protocol family and only provides “natural” (header) encapsulation.

DIAGNOSTICS

pcl%d: can't init. Insufficient UNIBUS resources existed to initialize the device. This is likely to occur when the device is run on a buffered data path on an 11/750 and other network interfaces are also configured to use buffered data paths, or when it is configured to use buffered data paths on an 11/730 (which has none).

pcl%d: can't handle af%d. The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped.

pcl%d: stray xmit interrupt. An interrupt occurred when no output had previously been started.

pcl%d: master. The TDM bus had no station providing ``bus master'' timing signals, so this interface has assumed the ``master'' role. This message should only appear at most once per UNIBUS INIT on a single system. Unless there is a hardware failure, only one station may be master at at time.

pcl%d: send error, tcr=%b, tsr=%b. The device indicated a problem sending data on output. If a ``receiver offline'' error is detected, it is not normally logged unless the option PCL_TESTING has been selected, as this causes a lot of console chatter when sending to a down machine. However, this option is quite useful when debugging problems with the PCL interfaces.

pcl%d: rcv error, rcr=%b rsr=%b. The device indicated a problem receiving data on input.

pcl%d: bad len=%d. An input operation resulted in a data transfer of less than 0 or more than 1008 bytes of data into memory (according to the word count register). This should never happen as the maximum size of a PCL message has been agreed upon to be 1008 bytes (same as ArpaNet message).

SEE ALSO
intro(4), inet(4)

HISTORY
The pcl interface appeared in 4.2BSD.