Page 3-14 400W Series Installation ManualRev. G 190-00356-02For all autopilots that are not listed in the 400W/500W Series AML STC, select the appropriate limitationas follows:Limitation [1] is checked for any installation that meets all of the following criteria:• The GPS SELECT discrete is set to ‘Prompt’ on the Main System Config Page (refer to section5.3.3. in the appropriate installation manual).NOTEThe 400W/500W Series GPS SELECT discrete output is connected to the GPS Selectinput (or equivalent) on the autopilot. This input is used by the autopilot to determine ifthe navigation source is GPS or VLOC. The autopilot typically goes to “wings-level”mode automatically when the navigation source changes between GPS and VLOC. Inorder to prevent the autopilot from entering “wings-level“ mode without the pilotnoticing the mode change, the unit prompts the pilot and requires pilot acknowledgementprior to switching the output signal state. Examples of autopilots that support this inputare the Honeywell KAP 140 or KFC 225.Limitation [2] is checked for any installation that meets all of the following criteria:• The GPS SELECT discrete output is configured for ‘Auto’ on the Main System Config Page(refer to section 5.3.3. in the appropriate installation manual).• ARINC 429 GPSS provided directly to the autopilot computer or through a roll-steeringconverter.• The 400W/500W interface to the autopilot provides vertical deviation information.Limitation [3] is checked for any installation that meets all of the following criteria:• The GPS SELECT discrete is set to ‘Auto’ on the Main System Config Page (refer to section5.3.3. in the appropriate installation manual).• GPS roll-steering information is not provided to the autopilot computer.• The 400W/500W interface to the autopilot provides vertical deviation information.Limitation [4] is checked for any installation that meets all of the following criteria:• The GPS SELECT discrete is set to ‘Auto’ on the Main System Config Page (refer to section5.3.3. in the appropriate installation manual).• The 400W/500W interface to the autopilot provides no vertical deviation information (this is thecase for autopilots with LNAV and altitude hold modes only i.e. the autopilot does not providevertical capture and/or vertical tracking).