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5 PTC-Firmware

5.4

Simultaneous STBY mode

In the STBY condition, the PTC automatically knows if it is called in AMTOR or
PACTOR, answering in the respective mode. It is possible to use the

ARX

command to

suppress the AMTOR reaction (In ARQ as well as FEC).

The

SCS

-PTC offers the possibility to receive AMTOR FEC and NAVTEX

transmissions from the STBY condition. For this, the

parameter must be set to 1. The

reading of AMTOR FEC and NAVTEX can be inhibited with the

ARX

command,

independently from

5.5

Specialities of the PTC-IIex

As the PTC-IIex is a single port unit some items have to be cared of when choosing
Packet-Radio operation or the HF modes, especially that simultaneous operation of
Packet and the HF modes in not possible.
In terminal mode the command-prompt (

cmd:

pac:, aud:

) indicates if the PTC-IIex is

available for the HF modes, or if the DSP is actually programmed for Packet-Radio
operation (there is only one exception, described below). If the

pac:-

menu is choosen out

of the STBY condition (

cmd:

) then the DSP is always reprogrammed for Packet-Radio

operation and the prompt takes the form

pac:

. However, it is always possible from the

cmd:-

menu to pass a command the the Packet-Radio side (without getting the DSP

reprogrammed) by preceeding the command with

pac.

cmd:

PAC

DB0GV <RETURN>

This command out of the

cmd:-

menu leads to a connect attempt to DB0GV on Packet-

Radio. This command is only accepted if there is

PACTOR or AMTOR connect

already running on HF, otherwise an error-message is displayed. When the command is
accepted, automaticly the DSP is switched to Packet-Radio operation and the

pac:-

is activated.
In fact, the PTC-IIex automaticly loads the required DSP code dependent on the
requirement of the recent command. At entry of the

Connect

command the user needs

not to care in which condition the DSP modem currently is. But when the user tries to
establish a Packet-Radio connect while a PACTOR connect is in progress the PTC-IIex
gives an error-message. Same in the opposite case, when a Packet-Radio connect exists
and the user tries to leave the

pac:-

menu with quit, this will also cause an error message.

However, it is possible to enter the

pac:-

menu when a PACTOR connect is running, but

in this case the DSP is not reprogrammed and the Packet-LED will not light. That means,
with a running connect on the HF side it is possible to change parameters being valid for
Packet-Radio. Only a

Connect

will be rejected in this case.

Although the PTC-IIex is limited for being a single port unit, it is very flexible also when
operating in Hostmode. Same as in the terminal mode it

automaticly

selects the

appropriate modem DSP code, dependent on the connect attempt entered by the user. If
one tries to establish simultaneous connects on HF and Packet-Radio an error message is
displayed.
As a special feature the PTC-IIex also accepts the commands

and

in hostmode to

provide the possibility to change the mode without connect attempt. This is for example
necessary to receive connects in the desired mode. It is useful to implement one of the
commands into the startup file of the hostmode-program, to ensure the prefered PTC-IIex