pcf(4)

NAME

pcf −port configuration file, used by DDFA software

Description

This file is used by the HP Datacommunications and Terminal Controller (DTC) Device File Access (DDFA) software to configure individual DTC ports. pcf is the generic name of the template file. In practice it is renamed for each port that needs different configuration values, and the values are altered appropriately for the device attached to the port. The pcf is referenced by an entry in the Dedicated Ports file (dp). The Dedicated Port Parser (dpp) parses the dp file and calls the Outbound Connection Daemon (ocd) program to spawn a daemon for each valid line in the dp file. A valid line is one in which the fourth field is the name of a pcf.

The master pcf is /etc/newconfig/ddfa/pcf, and should only be referenced in the dp file if the default values it contains are correct for the ports. If different values are needed, /etc/netconfig/ddfa/pcf should be copied to another directory and the copy should be modified and referenced in dp. The recommended procedure is to create the directory /etc/ddfa to hold the pcfs and the modified dp file.

Refer to ddfa(7) for information on how to configure and install the DDFA software.

The file consists of the names of variables and their values. The variables are shown terminated by a colon (:), but this is not mandatory. A variable and its value can be separated by spaces or tabs. Only one variable-value pair is allowed per line. Only the value should be altered; the variable name should not be changed.

The file contains the following information:

telnet_mode: This can have the value disable or enable. When it is enabled, data transfer over the network use the Telnet protocol. This option must be enabled for the DTC.

timing_mark: This can have the value enable or disable. When it is enabled, a telnet timing-mark negotiation is sent to the DTC after all user data has been transferred. ocd waits for a reply to the timing mark negotiation before closing the connection. This ensures that all data has been output from the DTC buffers to the device before the buffers are flushed. It should therefore be enabled for the DTC.

telnet_timer: This defines the time, in seconds, during which the software waits for a response to the telnet timing mark and binary negotiation. If the timer expires, an error message is logged to /usr/adm/syslog and the error is transmitted to the user application.

binary_mode: This can have the value disable or enable. When it is enabled, data transfer over the network is in binary mode, and treatment of special characters (such as XON/XOFF ) is disabled.

Due to the absence of flow control, data integrity cannot be guaranteed when binary_mode is enabled.

Note that even if binary_mode is disabled, it can be negotiated at any time by the application setting IXON to 0 in the termio data structure.

open_tries: This defines the number of times the software tries to open a connection before giving up. If the value is 0 the software tries “forever” (approximately 68 years). If the retry process fails, an error message is logged to /usr/adm/syslog. The error message is also transmitted to the user application.

The retry process can be interrupted by sending the SIGUSR2 signal to the ocd process using kill -17 pid.

Note that if the application exits after asking ocd to open the connection to the DTC, ocd continues trying to open until open_tries and/or open_timer are exceeded.

open_timer: This defines the time in seconds between tries. If the value is 0, ocd uses an exponential retry period algorithm up to 32 seconds; i.e., 1 2 4 8 16 32 32 32 ...

close_timer: This defines the time in seconds between the close call made by the application on the pty slave and the moment when the connection is actually closed. Setting this value to, for example, 5 seconds avoids the overhead of opening and closing the connection when a spooler spools several files at a time. Setting a sufficiently high value effectively leaves the connection permanently open.

status_request: This can have the value disable or enable. When it is enabled, the software sends a status request to the device attached to the server and processes the reply as follows:

LP_OK (0x30) ocd continues processing.

LP_NO_PAPER (0x31)
ocd retries within the limits of the status timer.

LP_BUSY (0x32)
ocd retries within the limits of the status timer.

LP_OFF_LINE (0x23)
ocd retries within the limits of the status timer.

LP_DATA_ERROR (0x38)
ocd retries within the limits of the status timer.

status_timer: This defines the time, in seconds, after which the software no longer waits for the reply to the status request. If the timer expires, an error message is logged to /usr/adm/syslog. The error condition is also transmitted to the user application.

eight_bit: This can have the value enable or disable.

Normally, data bytes processed by the pty have bit 7 stripped. If eight_bit is enabled, the stripping is disabled. If eight_bit is disabled, stripping is enabled, and bit 7 is stripped. This can also be achieved by changing the pseudonym’s termio structure using ioctl() commands.

tcp_nodelay: This can have the value enable or disable.

If it is enabled, data is sent to the LAN as it is received. It can be disabled if the software is sending packets faster than the server can accept.

The default values are:

telnet_mode     enable
timing_mark     enable
telnet_timer    120
binary_mode     disable
open_tries      1500
open_timer      30
close_timer     0
status_request disable
status_timer    30
eight_bit       disable
tcp_nodelay     enable

FILES

/etc/dpp
/etc/ocdbug
/etc/ocd
/etc/dpp_login.bin
/etc/utmp.dfa
/etc/newconfig/ddfa/pcf
/etc/newconfig/ddfa/dp

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pcf(4)

NAME

Description

FILES

SEE ALSO