Timewave DSP-232, Operating Manual

Page: 104 / 271

Chapter 5 Packet Operation
PERSIST works with PPERSIST and SLOTTIME to achieve true p-persistent CSMA (Carrier-Sense Multiple
Access) in packet operation.
PPersist ON | OFF Default: ON
Mode: packet Host: PP
ON
The DSP uses p-persistent CSMA (Carrier Sense Multiple Access).
OFF The DSP uses DWAIT for TAPR-type 1-persistent CSMA.
With
PPERSIST ON
, the DSP uses the
PERSIST
and
SLOTTIME
parameters for p-persistent CSMA instead of
the older DWAIT CSMA procedure.
When your computer has queued data for transmission, the DSP monitors the DCD signal from its modem. When
the channel clears, the DSP generates a random number between 0 and 255. If this number is less-than or equal to
PERSIST , the DSP transmits all the frames in its queue. If the random number is greater than “P”, the DSP waits
.01 x
SLOTTIME
(seconds) and repeats the attempt.
PPERSIST
can be used in both
KISS
and normal AX.25 operation.
QHpacket n Default: 10 (Modem 10)
Mode: packet Host: QH
n
Modem number to be selected when the HF Packet mode is entered.
QHPACKET sets the DSP-232 modem that will automatically be selected when the HF Packet mode is entered. To
enter HF packet mode, type:
HBAUD 300
.
See PACKET and MODEM commands for more infromation.
QVpacket n Default: 12 (Modem 12)
Mode: packet Host: QV
n
Modem number to be selected when the VHF Packet mode is entered.
QVPACKET sets the DSP-232 modem that will automatically be selected when the VHF Packet mode is entered.
To enter the VHF packet mode, the VHF commands must be ON for the selected Radio Port.
See the PACKET and MODEM commands for more information.
RAWhdlc ON/OFF Default: OFF
Host: RW
ON
The DSP operates in a raw HDLC packet mode when HOST is ON.
OFF The DSP operates in standard AX.25.
The RAWHDLC command enables the DSP-232 to bypass the AX.25 packet implementation and communicate
directly with the hardware HDLC (Z8530). HOST mode must be ON to communicate with the DSP-232 in the
RAW HDLC mode.
RELink ON
|
OFF
Default: OFF
Mode: packet Host: RL
OFF The DSP won’t attempt to re-establish the failed link.
ON
The DSP will try to automatically reconnect to the other station after the link has timed out on retries.
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