Data Sheet ACM/EXT/001 Extender Board Data Sheet Download Resource Login to download this resource Username Enter your Curtiss-Wright Defense Solutions username. Password Enter the password that accompanies your username. Forgot password? Don’t have an account? Register here. The ACM/EXT/001 is used to extend the Acra KAM-500 backplane so that user-modules can operate external to (above) the Acra KAM-500 chassis. This card is intended as a debug tool for customers developing their own Acra KAM-500 user-modules.