This outputs have Two different functions, it may be used as:
1- Sensor Supply output
2- Oil Level measurement

1- Sensor Supply output

This function is common for all SENSOR SUPPLY outputs of the POWER ECU ( more Details ).

2- Oil Level measurement

This document aims at describing how the Oil level measurement is processed on ActiMux Power ECU. It intends to provide help for application design under ActiGraf. Oil level measurement function is allowed on Power ECU Sensor Power Supply output. Measurement principle consists in supplying a stabilized current to an "hot wire" sensor and to process 2 measurements of the delivered voltage. Measurements are separated by a user-defined time interval that is accurate enough to guarantee measurement reproducibility. ActiGraf offers an interface to 2 parameters : "Measure Interval " and " Generated Current " that should be adapted to the sensor characteristics. Three variables are also used : "Voltage difference", "Start Measure" and " Measure Ready ".

Measurement process is activated by a rising edge on the "Start Measure " variable. First, a current which value has been set thanks to parameter "Generated current" is supplied to the sensor and the flag " Measure Ready " is reset to 0. After a constant stabilisation time, voltage measurement 1 is processed. Voltage measurement 2 is processed after that a period of time length defined by "Time Interval " user parameter has been elapsed. Supplied current is then shut down. Once voltage difference is available through the " Voltage difference " variable, "Measure Ready " flag is finally set to 1. If an error occurred during acquisition process or value calculation, " Measure Ready "stays low. Measurement relaunch operation is done by a toggling sequence on "Start Measure " command bit (new rising edge applied to the command). Due to "hot wire" measurement method, consecutive measurement should be implemented with caution to sensor post-heat time.