fgdata/Aircraft/Instruments-3d/FG1000/GFC700-lateral-FSM.xml

<PropertyList>

<!-- GFC 700 Autopilot Finite State Machine for LATERAL mode-->
<branch>/autopilot/GFC700/FSM/lateral</branch>

<state>
  <name>OFF</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value></value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value></value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value></value>
  </enter>
  <enter>
    <!-- Reset button to avoid triggering next transition immediately -->
    <command>property-assign</command>
    <property>/autopilot/lateral-mode-button</property>
    <value></value>
  </enter>
</state>

<state>
  <!-- Roll mode.  Either set wings level (if roll < 6.0), or set to current roll -->
  <name>ROL</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>ROL</value>
  </enter>
  <enter>
    <!-- Reset button to avoid triggering next transition immediately -->
    <command>property-assign</command>
    <property>/autopilot/lateral-mode-button</property>
    <value></value>
  </enter>
</state>

<transition>
  <!-- Go to wings level mode if roll [-6.0,6.0] -->
  <name>ROL-ROL-WL</name>
  <source>ROL</source>
  <target>ROL-WL</target>
  <condition>
    <less-than>
      <property>/autopilot/internal/filtered-roll-deg</property>
      <value>6.0</value>
    </less-than>
    <greater-than>
      <property>/autopilot/internal/filtered-roll-deg</property>
      <value>-6.0</value>
    </greater-than>
  </condition>
</transition>

<transition>
  <!-- Otherwise, just got to ROLL with the set roll value -->
  <name>ROL-ROL-SET</name>
  <source>ROL</source>
  <target>ROL-SET</target>
  <condition>
    <or>
      <greater-than>
        <property>/autopilot/internal/filtered-roll-deg</property>
        <value>6.0</value>
      </greater-than>
      <less-than>
        <property>/autopilot/internal/filtered-roll-deg</property>
        <value>-6.0</value>
      </less-than>
    </or>
  </condition>
</transition>

<state>
  <name>ROL-SET</name>
  <!-- Roll hold mode.  We assign a filtered value, which limits to to [-22.0, 20.0] -->
  <enter>
    <command>property-assign</command>
    <property n="0">/autopilot/settings/target-roll-deg</property>
    <property n="1">/autopilot/internal/filtered-roll-deg</property>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>roll-hold</value>
  </enter>
</state>

<state>
  <name>ROL-WL</name>
  <!-- Roll hold mode - wings level.  Used if the roll value when enabled is [-6,6]-->
  <enter>
    <command>property-assign</command>
    <property>/autopilot/settings/target-roll-deg</property>
    <value>0.0</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>roll-hold</value>
  </enter>
</state>

<state>
  <name>GA</name>
  <!-- GA mode - Wings level -->
  <enter>
    <command>property-assign</command>
    <property n="0">/autopilot/settings/target-roll-deg</property>
    <value>0.0</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>roll-hold</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>GA</value>
  </enter>
  <enter>
    <!-- Reset button to avoid triggering next transition immediately -->
    <command>property-assign</command>
    <property>/autopilot/lateral-mode-button</property>
    <value></value>
  </enter>
</state>

<state>
  <name>HDG</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>dg-heading-hold</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>HDG</value>
  </enter>
  <enter>
    <!-- Reset button to avoid triggering next transition immediately -->
    <command>property-assign</command>
    <property>/autopilot/lateral-mode-button</property>
    <value></value>
  </enter>
</state>

<!-- Common state for NAV from which the NAV source is used to transition to GPS, NAV1 or NAV2 autopilots -->
<state>
  <name>NAV-SRC</name>
  <enter>
    <!-- Reset button to avoid triggering next transition immediately -->
    <command>property-assign</command>
    <property>/autopilot/lateral-mode-button</property>
    <value></value>
  </enter>
</state>

<transition>
  <name>NAV-GPS</name>
  <source>NAV-SRC</source>
  <target>GPS-ARM</target>
  <condition>
    <equals>
      <property>/autopilot/settings/nav-mode-source</property>
      <value>GPS</value>
    </equals>
  </condition>
</transition>

<transition>
  <name>NAV-LOC</name>
  <source>NAV-SRC</source>
  <target>LOC-ARM</target>
  <condition>
    <or>
      <and>
        <equals>
          <property>/autopilot/settings/nav-mode-source</property>
          <value>NAV1</value>
        </equals>
        <equals>
          <property>/instrumentation/nav[0]/nav-loc</property>
          <value>true</value>
        </equals>
      </and>
      <and>
        <equals>
          <property>/autopilot/settings/nav-mode-source</property>
          <value>NAV2</value>
        </equals>
        <equals>
          <property>/instrumentation/nav[1]/nav-loc</property>
          <value>true</value>
        </equals>
      </and>
    </or>
  </condition>
</transition>

<transition>
  <name>NAV-VOR</name>
  <source>NAV-SRC</source>
  <target>VOR-ARM</target>
  <condition>
    <or>
      <and>
        <equals>
          <property>/autopilot/settings/nav-mode-source</property>
          <value>NAV1</value>
        </equals>
        <equals>
          <property>/instrumentation/nav[0]/nav-loc</property>
          <value>false</value>
        </equals>
      </and>
      <and>
        <equals>
          <property>/autopilot/settings/nav-mode-source</property>
          <value>NAV1</value>
        </equals>
        <equals>
          <property>/instrumentation/nav[1]/nav-loc</property>
          <value>false</value>
        </equals>
      </and>
    </or>
  </condition>
</transition>

<state>
  <name>GPS-ARM</name>
  <!-- GPS isn't referenced directly.  Instead we slave it to Nav1 and use the Nav1 autopilot -->
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value>GPS</value>
  </enter>
</state>

<transition>
  <name>GPS-ARM - GPS</name>
  <source>GPS-ARM</source>
  <target>GPS</target>
  <condition>
    <equals>
      <property>/autopilot/internal/nav-capture</property>
      <value>1</value>
    </equals>
  </condition>
</transition>

<state>
  <name>LOC-ARM</name>
  <enter>
    <command>property-assign</command>
    <property>/instrumentation/nav[0]/slaved-to-gps</property>
    <value>0</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value>LOC</value>
  </enter>
</state>

<transition>
  <name>LOC-ARM - LOC</name>
  <source>LOC-ARM</source>
  <target>LOC</target>
  <condition>
    <equals>
      <property>/autopilot/internal/nav-capture</property>
      <value>1</value>
    </equals>
  </condition>
</transition>

<state>
  <name>VOR-ARM</name>
  <enter>
    <command>property-assign</command>
    <property>/instrumentation/nav[0]/slaved-to-gps</property>
    <value>0</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value>VOR</value>
  </enter>
</state>

<transition>
  <name>VOR-ARM - VOR</name>
  <source>VOR-ARM</source>
  <target>VOR</target>
  <condition>
    <equals>
      <property>/autopilot/internal/nav-capture</property>
      <value>1</value>
    </equals>
  </condition>
</transition>

<state>
  <name>GPS</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>GPS</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value></value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/instrumentation/nav[0]/slaved-to-gps</property>
    <value>1</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>nav-hold</value>
  </enter>
</state>

<state>
  <name>LOC</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>LOC</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value></value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>nav-hold</value>
  </enter>
</state>

<state>
  <name>VOR</name>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode</property>
    <value>VOR</value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/annunciator/lateral-mode-armed</property>
    <value></value>
  </enter>
  <enter>
    <command>property-assign</command>
    <property>/autopilot/locks/heading</property>
    <value>nav-hold</value>
  </enter>
</state>

<!-- From the OFF state, pressing any of FD, AP, CWS, NAV, BC, APR, changes to ROL mode -->
<transition>
  <name>OFF-ROL</name>
  <source>OFF</source>
  <target>ROL</target>
  <exclude-target>true</exclude-target>
  <condition>
    <or>
      <equals><property>/autopilot/lateral-mode-button</property><value>FD</value></equals>
      <equals><property>/autopilot/lateral-mode-button</property><value>CWS</value></equals>
      <equals><property>/autopilot/lateral-mode-button</property><value>NAV</value></equals>
      <equals><property>/autopilot/lateral-mode-button</property><value>BC</value></equals>
      <equals><property>/autopilot/lateral-mode-button</property><value>APR</value></equals>
      <equals><property>/autopilot/lateral-mode-button</property><value>HDG</value></equals>
    </or>
  </condition>
</transition>

<transition>
  <name>OFF-HDG</name>
  <source>OFF</source>
  <target>HDG</target>
  <exclude-target>true</exclude-target>
  <condition>
    <or>
      <equals><property>/autopilot/lateral-mode-button</property><value>HDG</value></equals>
    </or>
  </condition>
</transition>

<!-- AP/FD logic is somewhat complex:
1) Pressing AP toggles the autopilot on/off
  a) OFF to ON : OFF-AP-ROL transition below
  b) ON to OFF : Handled by a separate FSM.  We could use a series of transitions
     to the same states below, but that would result in entry bindings being repeated, which would be bad
2) When the AP is enabled, the FD button is disabled. (Easy - no transition!)
3) Pressing the FD button when the FD is enabled switches off the FD : Switch-off transition below
-->

<!-- From the OFF state, pressing AP changes to ROL mode, with the AP enabled (e.g. not passive mode) -->
<transition>
  <name>OFF-AP-ROL</name>
  <source>OFF</source>
  <target>ROL</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>AP</value></equals>
  </condition>
  <binding>
    <command>property-assign</command>
    <property>/autopilot/locks/passive-mode</property>
    <value>0</value>
  </binding>
</transition>

<!-- From any state pressing FD when FD is ON switches off the FD -->
<transition>
  <name>FD-Switch-off</name>
  <target>OFF</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>FD</value></equals>
    <equals><property>/autopilot/locks/passive-mode</property><value>1</value></equals>
  </condition>
</transition>

<!-- Series of transitions to handle case where disabling the AP.  Need to remain in existing state -->

<!-- From any state, pressing GA goes to GA mode, and returns to ROL mode when pressed again -->
<transition>
  <name>To GA</name>
  <target>GA</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>GA</value></equals>
  </condition>
</transition>

<transition>
  <name>From GA</name>
  <source>GA</source>
  <target>ROL</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>GA</value></equals>
  </condition>
</transition>

<!-- From any state, pressing HDG goes to HDG mode, and returns to ROL mode when pressed again -->
<transition>
  <name>To HDG</name>
  <target>HDG</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>HDG</value></equals>
  </condition>
</transition>

<transition>
  <name>From HDG</name>
  <source>HDG</source>
  <target>ROL</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>HDG</value></equals>
  </condition>
</transition>

<!-- From (just about) any state, pressing NAV or APR goes to NAV mode.  APR mode should
     have a slightly different VOR version (VAPP), but is otherwise identical in lateral,
     if not vertical modes.  So we will just overload the states for simplicity. -->
<transition>
  <name>To NAV</name>
  <target>NAV-SRC</target>
  <exclude-target>true</exclude-target>
  <condition>
    <and>
      <or>
        <equals><property>/autopilot/lateral-mode-button</property><value>NAV</value></equals>
        <equals><property>/autopilot/lateral-mode-button</property><value>APR</value></equals>
      </or>
      <not><equals><property>/autopilot/locks/heading</property><value>nav-hold</value></equals></not>
    </and>
  </condition>
</transition>

<!-- Only switch off NAV/APR when NAV is pressed, as user may press APR to enable glideslope while already
     in NAV mode -->
<transition>
  <name>From NAV</name>
  <source>GPS-ARM</source>
  <source>VOR-ARM</source>
  <source>LOC-ARM</source>
  <source>GPS</source>
  <source>VOR</source>
  <source>LOC</source>
  <target>ROL</target>
  <exclude-target>true</exclude-target>
  <condition>
    <equals><property>/autopilot/lateral-mode-button</property><value>NAV</value></equals>
  </condition>
</transition>

</PropertyList>