User guide

MS-DMT Guide v1.04
Released 05-30-2014
82
are required. For those radio models that require handshaking, the appropriate handshaking is
hard coded for the radio type selected and not user selectable.
You can also set the CAT com port to 0 temporarily to run another program, this is faster than
shutting down the MS-DMT to start another program and also alleviates the possibility of
shutting down and starting the next program too fast and having com port access issues.
It is best to always set the data rate for the CAT com port to the highest rate supported by the
radio to minimize latency, this is especially true if CAT PTT is being used or CAT commands are
being sent in support of automatic Data/Voice port selection.
Radio PTT
The software provides for user selectable RS232 DTR/RTS line hardware PTT as well as CAT PTT
and or no software controlled PTT.
The first time the program is started CAT com port is set to 0, thus the software provides no
type of PTT support. This is often the only configuration used with fast VOX based external
interfaces providing a source of hardware PTT. However even if CAT PTT support is not required,
for some make/model radios with dedicated digital ports, CAT support may be desired to
automate the switching between the digital port for TX and back to the Mic port on RX for
mixed Data/Voice nets.
The PTT pull down menu is used to select the PTT mode if the CAT com port is active. By default
when the program is first used, EXTERNAL is selected. The choices are CAT ONLY, CAT&RS232,
RS232 and EXTERNAL.
For RS232 or CAT&RS232 selections, by default DTR/RTS is not checked, as such if the serial port
is other than 0, RTS will be selected, if DTR/RTS is checked, DTR will be selected. Should an