Built-in Test Equipment (BITE) & Automatic Test Equipment

Built-in Test Equipment (BITE) & Automatic Test Equipment (ATE)

As electronics progressed and sophisticated electronic equipment was designed, it necessitated a system to detect its performance and faults automatically. The BITE and ATE systems were developed for detecting faults and generating messages for users. Let's know about BITE and ATE.

Built-in test equipment (BITE)

BITE (Built-in Test Equipment) is a self-test function that is integrated into airborne or modern electronic equipment as a problem indicator. In most cases, BITE is designed as a signal flow test. Warning notifications indicate a fault has occurred if the signal flow is interrupted or deviates outside of acceptable levels.

BITE Functions

The BITE includes the following capabilities and functions:

Real-time, critical monitoring
Continuous display presentation
A sampled recorder readout Isolation of failures in modules and/or subassemblies
Verification of system status
Go/no-go alarms
Displays of quantitative data
Degraded operation status
Percentage of functional deterioration.

One of the best examples of BITE application is the Airbus ECAM system, which provides continuous fault monitoring and indicating for flight crew.

BITE in Airbus ECAM

The Electronic Centralised Aircraft Monitoring System (ECAM) keeps track of a range of aircraft systems and gathers data on a regular basis. While ECAM automatically alerts the flight crew to any faults, the crew can also manually select and monitor particular systems. The system test facilities on the maintenance panel in the cockpit, as well as the BITE facility on each computer, can be used by maintenance staff to follow up on failure messages recorded by the flight crew. The majority of these computers are housed in the avionics bay of the plane.

Automatic test equipment (ATE)

The ATE is a dedicated ground test instrument that can perform a wide range of tests and functional checks on an LRU or printed circuit board. ATE gathers a significant amount of data fast by making a large number of simultaneous connections with the equipment under test, minimising the requirement for a large number of human measurements to determine the functional status of an item of equipment.

ATE systems are typically dedicated to a single avionics system and are costly to develop and produce. As a result, original equipment manufacturers (OEMs) and qualified repairers are the only ones who use them.

ATE systems typically include computer control with displays that show what additional action (maintenance or adjustment) is required to keep the equipment in good working order. Finally, it's worth mentioning that, following an initial ATE diagnosis, individual pieces of equipment may require additional comprehensive tests and measurements.