56
Programmable I/O Lines
TM8000 3DK Hardware Developer’s Kit
Application Manual
September 2003
© Tait Electronics Ltd
3.1.13
Preset Channel
Application
This input signal is used to temporarily select a pre-programmed channel.
When this input line is deactivated, the radio returns to the channel it was
on at the time the input line was activated. This allows temporary channel
change for purposes such as transmitting GPS data on a data channel instead
of the voice channel.
Configuration
1.
Configure a list of channels.
2.
Configure an input line and associate it with this action. Set the active
state (high or low) and the debounce time (0 to 100ms).
3.
On the same form, select the preset channel. Hidden channels are also
available for selection. Scan group IDs are not available.
Timing
Allow debounce time plus 2ms plus time for channel change (typically
10ms) for the preset channel to be selected or to return to the previous
channel. If timing is critical in your application, then this will need to be
measured with the frequency step you intend to use.
Description
When the input line is activated, the currently selected channel ID is stored
for future use and the radio changes to the preset channel.
When the input line is deactivated, the radio returns to last selected channel.
While the input line is activated, the channel selection keys on the control
head are not functional.
If the input line is active while the radio is powered up, it must be re-applied
for the action to be carried out.
If a preset channel is selected and the radio powers down and up again then
the last selected channel will be selected and not the preset channel.
Related Actions
The ‘
’ input signal is used to change to a specified channel
number.
The ‘
’ input signal is used to permanently change to a
specified reference channel, which can be used to increment or decrement
from.
