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PK-88 OPERATING MANUAL
SLOTTIME 'n'
Parameters:
'n' -
0 to 250 specifies the time in ten-millisecond intervals during which the
PK-88 waits between generating random numbers to see if it can transmit.
The SLOTTIME parameter works with the PPERSIST and PERSIST parameters to achieve true
p-persistent CSMA (Carrier-Sense Multiple Access) in KISS TNC mode and in normal AX.25
operation. However, no real advantage will be obtained in AX.25 operation unless the
other stations on the channel are also using PERSIST and SLOTTIME.
See Chapter 6 for further discussion of SLOTTIME, PERSIST and KISS TNC protocols.
SQUELCH ON|OFF
Parameters:
ON -
The PK-88 responds to positive-going squelch voltage.
OFF -
The PK-88 responds to negative-going squelch voltage.
Normally, to decide if the channel is clear so that it can transmit, the PK-88 uses
its CSMA (Carrier Sense Multiple Access) circuit by sensing audio mark and space tones
from your packet receiver.
If there are signals other than packet on the channel you're using (such as voice
operation), it's possible that the PK-88 might not be quite as polite as it is
normally and transmit on top of the other signals.
The PK-88 can use true RF-carrier CSMA by monitoring the squelch line voltage from
your radio. This line can be easily connected in many radios to the 'busy' light or
indicator on the radio's front panel, or to other circuit locations that indicate the
presence or absence of carrier or received signals. Because your carrier-sensing
signal can be active-low or active-high (depending on the individual radio
manufacturer's design), you can set the PK-88 to sense either positive or negative
squelch voltages.
Mnemonic: SL
Mnemonic: SQ
5-82
Default: 10 (100 ms)
Default: OFF
COMMAND SUMMARY
PK88-164
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