DCL(4) BSD/hp300 Kernel Interfaces Manual DCL(4)NAMEdcl — HP 98628A communications link
SYNOPSIS
device dcl0 at scode? flags 0x1
DESCRIPTION
The 98628A is a buffered EIA RS-232C (CCITT V.28) communications inter‐
face. 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 inter‐
rupts happen on a per character basis.
The high water and low water marks in the kernel tty routines are com‐
pletely 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 then 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 ALSOtty(4)BUGS
Breaks received at a faster rate then 1 break every second will be recog‐
nized as a single break.
Console use is not supported.
The RS-422/423/499, MTS-DSN/DL modes of the card are not supported.
BSD June 9, 1993 BSD
