1. Test overview.

This test is used to verify that the subset " encoder wheel + sensor " of the film carrier functions correctly, and this in both directions of the motor.
For that, the motor will turn in one direction in order to make 6 revolutions of the encoder wheel, then the same in the opposite direction. An analysis of the values found by the encoder will allow to know if this subset functions correctly.
If this subset does not work, it is the whole of the ADDR system that will not function.

2. Test conditions.

This test relates to the APS film carrier inserted in the scanner.
The APS film carrier must be inserted in the scanner to carry out this test.
No film is necessary for this test.
The acceptance of the test is automatic.
No parameter is saved.

3. Pre-requirements.

The encoder wheel must be in the centre of the sensor, and especially not touch this one. Ensure that the encoder wheel is not buckled.

Explanation on the encoder wheel : The encoder wheel used in the film carrier has 500 tops per turn (1), which indicate the precise position of film + 1 top per turn (2) which indicates that one turn has just been made (1 turn corresponding to X mm of linear advance of film). The outside positions of the wheel (3) are not used.

4. Test realisation.

Click on RUN to execute the test. The motor will turn during a few seconds in one direction then a few seconds in opposite direction. This length of time corresponding in fact to 6 revolutions of the encoder wheel.
At the end, curves will be displayed , corresponds to the 6 times 500 positions of the encoder wheel, in one direction then in the other.

5. Test acceptance.

Acceptance criteria are displayed on the screen (identical for each direction of operation) :

• Encoder polarity : Check of the direction of operation: must be OK.
• Encoder samples : Numbers of measurements (6 times 500): must be = 3000.
• Encoder variance : must be different from 0.
• Timings average : must lie between 1000 and 1500.
• Timings slope : must lie between -2 and +2.

6. Other affected tests.

• APS Encoder 2.
• APS Cal RGB IR.
• APS ADDR.

7. Trouble shooting.

If The test is rejected : remove the protective plate and visually check that the wheel is well positioned in the sensor, that it does not touch it, that it is not buckled or that it is not damaged (in particular 500 positions). In this case, change it.