Timewave DSP-232, Operating Manual

Page: 51 / 271

Chapter 4 Terminal Interfacing
OFF The Host mode program must accept data from the DSP at anytime.
With
HPOLL ON , the Host mode program must poll the DSP—using ( CTRL-A ), O , G , G ,( CTRL-W )—for all data
that might be available to be displayed to the screen. With
HPOLL OFF
, the Host mode program must be able to
accept any data from the DSP whenever it becomes available.
KIss
n Default: 0
Host: KI
“
n ” Is a HEX number from $00 ( KISS disabled) through $FF that enables the KISS mode selected from the
table below.
The KISS mode must be entered to prepare the DSP for
KISS
operation. TCP/IP and other special applications have
been written that require the KISS mode be enabled to operate correctly. For normal AX.25 packet operation, this
command should be left at
0
or
OFF
(default).
The
KISS command, formerly ON | OFF , has now been expanded to a numerical value from $00-$FF. This
expansion supports G8BPQ’s multi-drop
KISS
protocol. The table below describes available
KISS
options.
KISS $00
:
KISS
disabled (formerly displayed as
KISS OFF
)
KISS $01 : Standard KISS (same as KISS ON or KISS YES)
KISS $03
: Extended
KISS
KISS $07 : Extended KISS + KISS polling enabled
KISS $0B
: Extended
KISS
+
KISS
checksum enabled
KISS $0F : Extended KISS + KISS polling and checksum enabled
Note that
KISS ON
enables standard
KISS
operation for compatibility with existing applications.
Extended
KISS
mode adds these commands to the standard commands ($x0-$x5):
$xC signifies data to be transmitted. Unlike the $x0 command, the $xC byte is followed by two frame
ID
bytes, then the data; when the TNC transmits the frame, it notifies the host application by echoing back
FEND, the $xC byte, the two frame
ID
bytes, and FEND.
$xE is the polling command, similar to the Host “GG” command existing in AEA products. Polling makes
multi-TNC
KISS
operation possible. If
KISS
polling is enabled, the TNC holds received data until the host
application sends the poll command. If the TNC is holding no data, it echoes back FEND $xE FEND. The
“x” in “$xE” must match the number in the
KISSADDR
command for the TNC to respond.
If the
KISS
checksum is enabled, a checksum byte is added to the end (before the final FEND) of all
KISS
blocks
flowing between the TNC and the host application. The checksum is the exclusive-OR of all other bytes between
the FEND bytes, taken before
KISS
escape transpositions. A checksum is helpful when using multiple TNCs on a
marginal RS-232 link. If the DSP receives a KISS block with a bad checksum, it does not transmit the data.
In
KISS and Raw HDLC modes, communication activity on the RS-232 link is shown by lighting the STA and
CON LEDs as follows:
Host to TNC Communication: STA LED illuminated.
TNC to Host Communication: CON LED illuminated.
Host
OFF
—entering three (
CTRL-Cs
)—will force
KISS OFF
. Details on the use of
KISS
TNC protocol are
contained in AEA’s Technical Refere n ce Manual — Model DSP-232 Data Controller .
KISSAddr
n Default: 0
Host: KA
4-18 September, 05