<?xml version="1.0" encoding="UTF-8"?>

<section xml:id="extOpenGD77Channel"
         xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude">


<info>
  <title>Channel extension</title>
</info>

<para>
  This extension allows to specify some channel settings specific for devices running the 
  OpenGD77 firmware. This extension can be added to any channel, analog and digital.
  For now, this extension only allows to specify the power for the channel in more detail.
</para>

<example>
  <title></title>
  <programlisting><![CDATA[channels:
  - digital:
      id: ch1
      name: Example channel 
      # all the other channel settings
      openGD77:
        power: P750mW 
]]></programlisting>
</example>

<para> 
  The OpenGD77 channel extension is a mapping named <token>openGD77</token>. It contains the 
  device specific settings for that channel. 
</para>


<section>
<info>
  <title>Channel attributes</title>
</info>

<para>
  For now, there are only few attributes specifying more detailed power settings and scan behavior for the 
  channel.
</para>

<variablelist>
  <title>Channel extension fields</title>
  <varlistentry>
    <term><token>power</token></term>
    <listitem>
      <para>Specifies the detailed power settings for the channel. This is one of the following 
        strings <token>Global</token>, <token>P50mW</token>, <token>P250mW</token>, <token>P500mW</token>, 
        <token>P750mW</token>, <token>P1W</token>, <token>P2W</token>, <token>P3W</token>, 
        <token>P4W</token>, , <token>P5W</token>, <token>Max</token>. Where <token>Global</token> 
        implies that the global power settings is used and <token>Max</token> the maximal possible 
        power is used (usually 7W on VHF and 5.5W on UHF). This power setting overrides the 
        common channel power setting. See <xref linkend="cpChannels"/>.</para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <token>scanZoneSkip</token>
      <token>scanAllSkip</token>
    </term>
    <listitem>
      <para>
        In contrast to the original GD-77 firmware, OpenGD77 does not implement scanning by scan 
        lists. Instead, either all channels defined in the radio or all channels within the current
        zone can be scanned. To exclude some channels from these scans, the 
        <token>scanZoneSkip</token> and <token>scanAllSkip</token> flags can be used. When enabled,
        the channel will be excluded from the respective scan.
      </para>
    </listitem>
  </varlistentry>
</variablelist>

</section>
</section>
        
