Page 36 of 101
DWG ID: 181-0101-00A
Date: 2003-09-26
digipeater and the response, if any, to travel back to the host. Note that the automatic
"Time to Live" timer and the TUPTIME timer are only in effect if packets are being
digipeated.
9.4.2
TUP Mode Operation
9.4.2.1
Commands Used
Basic TUP Operation involves just a few commands:
MYCALL - The MYCALL command determines the MODEM address. This must be
entered after the autobaud routine has detected an asterisk (*).
PACTIME - The PACTIME parameter determines how long the modem will wait after
receiving data to be transmitted from the DTE before beginning the radio key-up
sequence. Normally, this parameter should be set to AFTER 1 (100 ms) in order to
minimize "dead air" time on the system.
PACLEN - PACLEN sets the maximum size of the data packet(s). Most applications do
not require large amounts of data to be transferred so the default value (128) will
probably be satisfactory, allowing packets up to 128 bytes. If the amount of data to be
sent exceeds the PACLEN parameter setting, the transmission will be composed of
multiple packets containing the data.
PERSIST and SLOTTIME - These parameters determine how aggressively the modem
will attempt to access a multi-user channel based on carrier detect. See KPC-series
manual for a full explanation of these parameters.
9.4.2.2
Entering TUP Mode
Use the INTFACE command to begin TUP operation. Set the INTFACE command to
TUP:
cmd:INTFACE TUP <cr>
and turn the unit off and then back on.
9.4.2.3
Exiting TUP Mode
If you want to exit the TUP mode to "fine tune" parameter settings (or for any other
reason), the Command mode of the modem can be regained by using the transparent data
escape sequence, i.e., by sending a series of three control-Cs (unless a different control
character for COMMAND has been defined). (See TRANS command in Commands
section.
9.5
Poll Mode
