As a complement of the standardisation of sensor and actuator electrical interface (SAIF), the functional interface standardisation is seen as a key element for interoperability.

In particular, this is essential to streamline the software reference architecture and make it less sensitive to sensor actuators specificities.
This group brings together the software and the Control community, in view of giving to Control engineers the opportunity to be exposed to and to review the software architecture in terms of its impact on the Control behaviour, for example impact of delay or jitters, or use of some SOIS services, or use of Time and Space Partitioning, etc.

The WG brings its member to a common level of knowledge both on software architecture principle and on Control interface functional needs. The WG investigates existing sensors and actuators from the functional interface standpoint in order to detect any commonality for future standardisation. The functional interface is considered together with its impact or constraints on the software architecture, the electrical architecture, and the real-time performance, for example:

• identification of generic functional data stream (for on board control, for FDIR and for ground monitoring) for main AOCS sensors and actuators with requirements on delays, jitter, time stamps, TM oversampling or filtering etc.
• impact of the use of PUS/SOIS to command an equipment
• implementation of high frequency actuator command (chemical thruster 1ms steps, SADM microstepping) either directly by the On Board Computer or through a dedicated electronics

An exemple of common interface

Main types of sensor actuators are addressed (star trackers, earth and sun sensors, magnetometers, gyros, reaction wheels, magneto-torquers, thrusters, SADM, etc) with major European vendors but also some American vendors (in particular for gyro and reaction wheels).