Older curtains no longer calibrate, what can I do?
During the calibration of a potentiometer, we call for the OPEN function, and watch the change of resistance from the Pot. Once there is (I believe) a 5 second period of no change, we assume we have hit the end, and call for the CLOSE function, once the resistance stops changing for the time out period, the calibration is completed.
Therefore there are many possible types of Pot failures that can either cause the calibration to fail, or to complete but not complete properly.
On the AFX’s screen when you launch calibration, it will show an “ADC” value, this is the analogue to digital reading coming from the pot (not the resistance). This value should be steadily increasing or decreasing as it opens, then once it starts to close the value should go in the opposite direction.
This ADC value’s behavior can give you some indication as to if the pot as failed.
However the fool-proof way of testing the pot, is to measure the resistance value between your wiper (FB) wire and your positive or negative as the curtain or actuator does a full open and close. While measuring, you must ensure that the pot wires are disconnected from the controller, and your probes have a good stable connection with the wires. That way it doesn’t throw off the reading.
During this test, you may need to reconfigure your actuator/curtain to no feedback, that way you are able to manually override it to OPEN, IDLE, or CLOSE on demand.
Please also bear in mind that after you change your potentiometer, double check that the wiring is correct. I have seen so many times where a POT is changed, but the wires then get mixed up.