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PK-88 OPERATING MANUAL
CHECK 'n'
Parameters:
'n' -
0 to 250 specifies the check time in ten-second intervals.
0
-
Zero disables this feature.
CHECK sets a timeout value for a packet connection, and depends on the setting of
AX25L2V2.
Without the CHECK feature, if your PK-88 were linked or 'connected' to another station
and the other station seemed to 'disappear,' your PK-88 would remain in the connected
state indefinitely, refusing connections from other stations.
This might happen if propagation changes unexpectedly or an intermediate digipeater
station fails or is shut down while you and the distant station are connected 'via'
that digipeater.
Your PK-88 tries to prevent this situation from occurring by sending a new connect
request packet when RELINK is ON and the specified time elapses without any packets
being heard from the other TNC.
If RELINK is ON, when a pre-Version 2 link is inactive for (CHECK times ten seconds),
your PK-88 tries to save the link by starting a reconnect sequence. The PK-88 enters
the 'connect in progress' state and sends SABM (Connect Request) frames. In addition,
the PK-88 adds * random time of up to 30 seconds each time CHECK is used.
If AX25L2V2 is ON and packets have not been heard from the distant end for 'n'
times 10 seconds, your PK-88 sends a 'check packet' to test if the link still
exists to the other station.
The 'check' packet frame contains no information, but is interpreted by the distant
station's TNC to see if it is still connected. If the distant station's TNC is still
connected, the distant station sends an appropriate response packet.
If your PK-88 initiates the 'check' and does not get an answer after RETRY+l attempts,
the PK-88 starts a reconnect sequence just as if you had typed the CONNECT command. If
RELINK is OFF, the PK-88 goes to a disconnected state.
If AX25L2V2 is OFF and the other station has not been heard for
in' times 10 seconds, your PK-88 does not test the link to the
distant station; your PK-88 sends a reconnect packet just as if
you had typed the CONNECT command.
Mnemonic: CH
5-27
COMMAND SUMMARY
Default: 30
PK88-109
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