Chapter 5 Packet Operation
8Bitconv
ON
|
OFF
Default: OFF
Mode: packet/ASCII
Host: 8B
OFF
The high-order bit is stripped in Converse Mode.
ON
The high-order bit
isn’t
stripped in Converse Mode.
8BITCONV
permits packet and ASCII transmission of 8-bit data in Converse mode. When
8BITCONV
is
OFF
, the
high-order bit (bit 7) of characters received from the terminal is set to 0 (zero) before the characters are transmitted.
ACKprior
ON
|
OFF
Default: OFF
Mode: packet
Host: AN
ON
Priority
acknowledgment is enabled.
OFF
This feature is disabled.
This command implements the Priority acknowledge scheme described by Eric Gustafson, N7CL, which proposes
to improve multiple-access packet performance on HF and VHF simplex channels with “hidden” terminals. When a
busy channel clears, the
acknowledgments are sent immediately while data and poll bits are held off long enough to
prevent collisions with the
ack
packets. By giving priority to data
ack
s, fewer
ack
s will collide with other station’s
data, reducing retries. Digipeated frames are sent immediately.
RAWHDLC
and
KISS
force
ACKPRIOR
OFF
.
These are the defaults for a P-persistence system with no Priority
acknowledgment:
ack
PRIOR
OFF
,
PPERSIST
ON
,
PERSIST
63
,
SLOTTIME
30
,
RESPTIME
0
,
MAXFRAME
4
,
and
FRACK
5
.
The following are the recommended command settings for Priority
acknowledge:
1200 baud VHF packet
300 baud HF packet
ACKPRIOR
ON
ACKPRIOR
ON
PPERSIST
ON
PPERSIST
ON
PERSIST
84
PERSIST
84
SLOTTIME
30
SLOTTIME
8
RESPTIME
0
RESPTIME
0
MAXFRAME
1 - 7
MAXFRAME
1
FRACK
8
FRACK
15
HBAUD
1200
HBAUD
300
DWAIT -
doesn’t matter
DWAIT
-
doesn’t matter
Stations using neither the Priority
acknowledge nor the P-persistence schemes should set
DWAIT
73
for 1200 baud
and
DWAIT
76
for 300 baud work. Stations using P-persistence but not Priority
acknowledge should set
PERSIST
and
SLOTTIME
to the same values that
ACKPRIOR
stations are using.
AEA and TAPR use some different command names to handle P-persistence. The following table should help with
the AEA/TAPR command differences:
TAPR SLOTS
MFJ SLOTMASK
AEA PERSIST
Remarks
1 $00
255
Disables
slotting
2 $01
127
3
84
4 $03
63
Default setting
6
42
8 $07
31
Very busy channel
12
20
16 $0F
15
Extremely busy channel
64 $3F
3
September, 05
5-23
Summary of Contents for DSP-232
Page 120: ...Chapter 6 GPS Applications September 05 6 1...
Page 138: ...Chapter 7 Maildrop Operation 7 18 September 05...
Page 158: ......
Page 159: ...Chapter 8 ASCII and Baudot Operation September 05 8 1...
Page 185: ......
Page 186: ...Chapter 9 AMTOR Operation September 05 9 1...
Page 198: ......
Page 199: ...Chapter 10 Morse Operation September 05 10 1...
Page 207: ......
Page 208: ...Chapter 11 SIAM and NAVTEX Operation September 05 11 1...
Page 230: ......
Page 231: ...Chapter 12 PACTOR Operation September 05 12 1...
Page 240: ...Chapter 13 Troubleshooting September 05 13 9...
Page 254: ...Chapter 13 Troubleshooting 13 9...
Page 256: ...DSP 232 Manual Addendum September 05 AD 2...
Page 259: ...Appendix A Radio Connections Radio Connection Diagrams September 05 A 3...
Page 260: ...Appendix A Radio Connections A 4 September 05...
Page 261: ...Appendix A Radio Connections September 05 A 5...
Page 262: ...Appendix A Radio Connections A 6 September 05...
Page 263: ...Appendix A Radio Connections September 05 A 7...
Page 267: ...Appendix D Mailbox Upgrade September 05 D 2...
Page 268: ...Appendix E Schematics and Pictorial September 05 E 3...