9 Packet-Radio
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Because of this, KISS is not suitable for e.g. PACTOR: The timing-critical PACTOR
protocol cannot easily be implemented on a PC with multitasking operating system and
transported via a KISS interface to the modem.
Via KISS only Packet-Radio modems
can be accessed. PACTOR operation is not possible with KISS
. ATTENTION: As
soon as KISS mode is started, a running PACTOR connection is terminated immediately.
With the dual port PTC’s two KISS ports are available in parallel, with the KISS
addresses 0 and 1. (With SRP the Ring addresses are assigned automatically, see below.)
A complete description of the KISS protocol exceeds the limits of this update information
and can be found in relevant literature or in the Internet.
9.5.1
Activating KISS-mode, the commands KISS and @K
The KISS-Mode is activated with the commands
KISS
or alternatively
@K
out of the
normal command mode. This usually happens automatically by the KISS-PC-software or
a KISS capable controller (e. g. TNC3). The KISS-mode is terminated by a system reset
(power off/on cycle), but can also be terminated by software with sending the decimal
byte sequence 192, 255, 192. The termination by sending the byte sequence is usually
done automatically by the software as well, and may just once be configured correctly in
the setup of the program.
9.6
SMACK
SMACK
means “Stuttgart’s Modified amateur radio-CRC-KISS“. It represents a KISS
mode with added “checksum” for data protection. SMACK is supported by many KISS-
capable systems. To switch into the SMACK-mode, first the normal KISS more needs to
be entered. KISS-master and KISS-modem then automatically negotiate if CRC
protection (SMACK) can be enabled.
A complete description of the SMACK protocol exceeds the limits of this update
information and can be found in relevant literature or in the Internet.
9.7
SRP
SRP
means “Serial Ring Protocol“ and has been developed by Jimy Scherer, DL1GJI,
for XNET, respectively the TNC3. It is an extended SMACK with the possibility to
operate several “modems” together with one SRP master in a Token-Ring. This provides
the possibility of establishing a complex system of digipeaters. With this, e.g. two PTC-
IIpro can be operated on one TNC3 (as master) in a ring (network). The addresses (“ring
adresses“) of the single ports are assigned automatically. A dual ported modem (e.g. PTC-
IIpro) receives 2 ring addresses, e.g. 0 and 1, one address per port. The SRP master can
access both ports independently. With a ring of one TNC3 (without internal modems) and
two PTC-IIpro (as modems) four modem ports are available (physically provided by the
PTC-IIpro’s) for this digipeater. Two ports can e.g. be used for „Robust-Packet-Radio“
4
SMACK, http://www.nordlink.org/firmware/smack.txt
5
SRP, http://www.swiss-artg.ch/xnet/pdf/tnc.pdf