The Altimeter is an RVSM compliant instrument capable of operating in self-sensing or repeater mode. In the Control configuration, it can operate in the self-sensing (Standby) or repeater (Normal) mode as selected by the operator.
In the Monitor configuration, the Altimeter operates exclusively in the self-sensing mode, processing static pressure, barometric, and PSI correction factor input data to compute and display baro-corrected altitude (Hbc) and altimeter setting number (ASN) data. In the repeater mode, it displays ASN and Hbc computed from pressure altitude (Hp) data received from an IS&S 9B-81010-3 Digital Air Data Computer (DADC) via an ARINC 429 interface.
The Altimeter provides dedicated digital displays of Hbc and ASN and analog display of Hbc using a liquid crystal display (LCD) and an E/M controlled pointer. The altitude can be displayed in meters (M) or feet (ft) and the ASN can be displayed in millibars (MB) or inches of mercury (IN.HG) as selected by the operator. The LCD is provided with high intensity backlighting for daytime use and low level white lighting for nighttime viewing.
The Altimeter outputs altitude and baro correction data and performs altitude hold monitor and alert functions, as well as data checking, fault detection, and status indication functions. It is equipped with a multifunction PUSH SELECT Button used in selecting operating mode (Control configuration) and canceling fault indications. It also includes a BARO Set Knob for setting the ASN, an ME Button for setting the altitude and ASN display units, and a TEST Button for activating the instrument self-test and fault history display functions.