Ports: Cw; Ports: Ptt - microHAM DIGI KEYER Manual

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CW Port
By their very nature, USB ports are not well suited to transfer the real time events required for CW keying
on virtual serial port control signals (DTR). In addition to the latency in USB, there are also latencies
caused by computer CPU load, internal Windows message processing (inter-process communication) and
data flow from another peripherals using the USB ports. This can result in transmitted characters being
garbled. To minimize these unwanted operating system effects Router uses a specially developed
oversampling and prediction algorythm to assure the smoothest possible transfer of control signal events
over USB. Thanks to this principle, CW keying in the Router is in most cases usable up to 50 WPM if the
application generates keying signals accurately and does not consume 100% of CPU time at the highest
priority class.
Router allows assigning a virtual serial port for the CW channel DTR or RTS output control line.
TIP: More applications use DTR for CW than RTS.
When a COM port is assigned in the Router but not in the application (or the application is not running),
Router shows the channel as closed.
When an application opens the COM port (usually at start-up), Router shows the channel as open.
Activity and state of the CW channel is indicated by red
arrow. If port is opened, it does not mean that it is
properly configured for CW keying. The Red arrow will
light in time with the transmitted CW characters when port is properly configured in the application.
To test operation of CW from the computer to the radio click on Test button with no port assigned or the
port closed. More details about function checks are described in chapter 12.2
PTT Port
The PTT channel is used for T/R switching of the transceiver, Power Amplifier and Low Noise Preamplifier
(LNA). An internal T/R sequencer assures 100% protection against transmitting through the LNA or hot
switching of the PA when the PTT channel is used for T/R switching. More information about T/R
switching, DIGI KEYER PTT outputs and the sequencer is provided in chapter 15.3
Router allows assigning a virtual serial port to the PTT channel and supports PTT via DTR or RTS.
TIP: More applications use RTS for PTT than DTR.
When a COM port is assigned in the Router but not in
the application (or the application is not running),
Router shows the channel as closed.
When an application opens the COM port (usually at start-up), Router shows the channel as open.
Activity and the state of PTT channel is indicated by arrow. If port is opened, it does not mean that is
properly configured for PTT keying. The arrow will light during the entire transmission when port is
properly configured. Operation of the PTT outputs is described in chapter 15.3
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