The KMD-540 display used in the KMD-550 and KMD-850 Multi Function Display systems is capable of receiving magnetic from several sources. This heading information is used to correct the difference between heading and track based display pages to allow overlay of flightplan information and other data. Compatible heading sources include synchro XYZ, FMS/HDG, Traffic ARINC 429, digital heading via WX-500 Stormscope. According to the KMD-550/850 installation manual, synchro XYZ is the highest priority heading source. However, the KAC-504 traffic PCMIA card must be installed in the KMD-540 base unit for the XYZ heading to operate. Therefore, this card must be installed in the KMD-540 display to interface common heading systems such as the Collins PN-101 and Bendix/King KCS-305 & KCS-55A. The cost of the KAC-504 traffic card is $2000 list price. Click Here to view a page from the KMD-550/850 installation manual detailing these interfaces (Adobe Acrobat Reader required). The KMD-540 will utilize position information from many GPS or FMS sensors. It can be configured for either RS-232 or ARINC 429 as the position source depending on the PCMIA card configuration in the KMD-540. That is, the ARINC 429 source option requires the installation and configuration of the KAC-504 traffic card option in the KMD-540. Most GPS receivers output RS-232 information. This includes common receivers such as the Bendix/King KLN-89B / KLN-94 / KLN-90B / KLN-900, Garmin GPS-400 / GNC-420 / GNS- 530 / GPS-150XL / GPS-155 / GPS-155XL / GPS-165 / GNC-250 / GNC-250XL / GNC-300 / GNC-300XL and UPS/II Morrow GX-50 / GX-55 / GX-60 / GX-65. Flight Management Systems such as the Bendix/King GNS-X / GNS-XLS and the Universal UNS-1A, 1B, 1K only output ARINC 429 information. In addition all Garmin receivers and the Bendix/King KLN-90B, KLN-900 will output both RS-232 and ARINC 429 formats. Please note that if the KAC-504 card is installed, Honeywell recommends that the ARINC 429 source be used if available. Click Here to view a page from the KMD-550/850 installation manual detailing these interfaces (Adobe Acrobat Reader required). The KAC-504 card was used for the above interfaces because of its extended expansion capabilities (inputs and proessor). The other interface cards available for the KMD-540 do not have expansion potential. As of 7/1/02, Honeywell is reporting that WX-1000E Stormscope interface may be the next interface available for the KMD-540 via the KAC-504 card.