SCS PTC-IIex, Manual

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6 Commands
Chapter 6
6 Commands
6.1 ACheck (AMTOR Check)
Default setting: 30
Parameter: X 0... 100, SNR for AMTOR Packets.
This command allows a much sharper error checking than is possible with previous
AMTOR systems. By using the analogue information from the A/D converter, it is
possible to estimate the Signal/Noise ratio of the AMTOR blocks or the AMTOR CS
signals (noise in this sense meaning all unwanted signals). As soon as the SNR remains
under pre-set, the PTC assesses this packet as containing. This system has the advantage
that the amount of undetected errors with signals that contain heavy interference or noise
is drastically reduced.
The value range of the
ACheck
command extends between 0 and 100. The value 0
means the additional check is switched off. The value 100 gives the maximum restricted
reception. The standard value (30) allows a link, even with very weak signals, with,
however, markedly reduced printing errors. Higher values (40-60) are recommended for
APLINK, where data is sent over multiple AMTOR links, until the target box is reached,
and thus a minimum error rate is to be aimed at. Higher values can however cause a
problem when the resync rate climbs considerably. This leads to higher values of
transmitted errors, as every AMTOR resync also contains a built-in random component
(violation of the ARQ principle).
6.2 ADdlf
Default setting: 1
Parameter: 0 Auto LF inhibited.
1 Auto LF in Baudot RTTY and AMTOR.
2 Auto LF in Baudot RTTY, AMTOR and PACTOR.
Inserts an automatic <LF > on the transmission side. Some Baudot, RTTY, and AMTOR
stations require this to prevent the receiver overwriting lines, which occurs when only a
<CR> is transmitted by the PTC. (In PACTOR <CR> normally also contains the
NEWLINE function.)
6.3 Amtor
This command activates the
AMTOR
command prompt. Some commands are auto-
matically adjusted for the new mode. For example, Connect starts an AMTOR ARQ call.
The AMTOR SELCALL can be adjusted with the
MYcall
command. The
TR
command
becomes valid, etc.
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