DCL(4)

NAME
dcl - HP 98628A serial communications link

SYNOPSIS
dcl0 at dio? scode ? flags 0x1

DESCRIPTION
The 98628A is a buffered EIA RS-232C (CCITT V.28) communications interface. It has one port with full modem control.

Input and output for each line may set to one of following baud rates; 0, 50, 75, 110, 134.5, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200.

An optional argument flags may be set to 1 if the line should be treated as hard-wired with carrier always present, or to 0 if modem control is desired.

Use HP cable "98626 & 98628 opts.002, RS232-C DCE CABLE, 5061-4216" to attach non-modem devices. Use HP cable "98626 & 98628 opts.001, RS232-C DTE CABLE, 5061-4215" to attach modems.

The 98628A has a 256 byte input silo and a 256 output silo. Input interrupts happen on a per character basis.

The high water and low water marks in the kernel tty routines are completely inappropriate for a device like this with a large input buffer. Don't use tandem mode if possible. A fast system can handle input at 19.2K baud without receive overflow.

For output to devices that make heavy use of XON/XOFF a write size of less than 256 will improve performance marginally.

FILES
/dev/ttyl[0-9]

DIAGNOSTICS

dcl%d: error 0x%x RESET CARD. Where the errors are encoded:

    0x06 card failure
    0x0d uart receive overflow
    0x0e receive overflow
    0x0f missing external clock
    0x10 cts false too long
    0x11 lost carrier
    0x12 activity timeout
    0x13 connection not established
    0x19 illegal databits/parity
    0x1a register address out of range
    0x1b register value out of range
    0x-- unknown error

SEE ALSO
tty(4)

BUGS
The dcl device is not actually supported in NetBSD. This man page is only for information purposes in case someone wishes to port the driver from 4.3BSD.

Breaks received at a faster rate than 1 break every second will be recognized as a single break.

Console use is not supported.

The RS-422/423/499, MTS-DSN/DL modes of the card are not supported.