PK-88 OPERATING MANUAL
COMMAND SUMMARY
5 - 54
PK-88 - 129
PACLEN
n
Mnemonic:
PACL
Default: 128
Parameters:
n
0 to 255 specifies the maximum length of the data portion of a packet.
0
Zero is equivalent to 256.
PACLEN sets the maximum number of user data bytes to be carried in each packet's 'information
field'. 'User data' means the characters you actually type at your keyboard (or send from a stored
file).
The PK-88 automatically transmits a packet when the number of characters you type (or send from
disk) for a packet equals
n
. This value is used in both Converse and Transparent Modes.
Most keyboard-to-keyboard operators use the default value of 128 bytes for routine VHF/UHF
Packet services.
Experiment with different values for MAXFRAME and PACLEN to find the combination best suited to
your operating conditions – especially if you are transferring files.
The lower the value of PACLEN, the greater the probability of getting packets though the link
without 'hits' or retries.
Increase PACLEN to 256 byes (set 0) if transferring files to a nearby station over a high quality
path.
Reduce PACLEN to 64, or even 32 when working 'difficult' HF radio paths.
If the radio link is good, an optimal relationship will exist between the parameters set by these
commands. Set PACLEN so that the maximum number of characters outstanding doesn't ex-
ceed the receive buffer space of the TNC receiving the data.
It is not necessary that two TNCs be set to the same PACLEN value to exchange data; however,
some TNCs may not be compatible when frames contain more than 128 data characters.
NOTE:
The FRACK counter begins counting from the first flag of each frame. If MAXFRAME
is set to 7 and PACLEN is set to maximum (0), FRACK should be lengthened to pre-
vent the distant station's ACK from colliding with your possibly-premature retry.
PACTIME
EVERY|AFTER
n
Mnemonic:
PACT
Default: AFTER 10
Parameters:
n
0 to 250 specifies 100-millisecond intervals.
EVERY Packet timeout occurs every
n
times 100 milliseconds.
AFTER Packet timeout occurs when
n
time 100 milliseconds elapse without input
from the computer or terminal.
A PACTIME parameter is always used in Transparent Mode. PACTIME is also used in Converse
Mode if CPACTIME is ON.
When EVERY is specified, the characters you type or send from disk are packaged and queued
for transmission every
n
times 100 milliseconds.
When AFTER is specified, the characters you type or send from disk are packaged when input
from the terminal stops for
n
times 100 milliseconds.
A zero-length packet will never be produced. The timer is not started until the first character or
byte is entered.
A value of 0 (zero) for
n
is allowed; zero means packets are sent with no wait time.
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