Frequency inputs

[madships]

Trying to wire in wheelspeed sensors on to the x10- when I leave the connected sensors unassigned then voltage output is as I would expect when I spin the wheel (I.e. the sensor is registering the trigger teeth etc) but as soon as I assign the sensors to wheelspeed, the voltage is pulled to zero and I get no reading. It seems to be something to do with assigning it as wheel speed, as if I assign it to say a switch input then the sensor works as normal. Is this an issue with having the sensor on the x10, or am I missing something in the scal setup?

[TimH]

Wheel speed is not sent as a voltage; it's sent as a data value representing the frequency that's been measured by the X10.

[madships]

Ah, so it is normal for the raw voltage data to drop to zero once the sensor is assigned as a frequency sensor rather than a generic 5v? So I just need to look at different channels when setting it up? Will give it a go. Had assumed that the voltage signal would remain alongside the derived frequency signal.

[TimH]

Ah, so it is normal for the raw voltage data to drop to zero once the sensor is assigned as a frequency sensor rather than a generic 5v?

That's normal

So I just need to look at different channels when setting it up? Will give it a go. Had assumed that the voltage signal would remain alongside the derived frequency signal.

If you're assigning an X10 input for a wheel speed (for example), set it up as required, then assign a gauge to that wheel speed. I think that's only way to monitor it (so you'll have to spin the wheel; or use a signal generator to emulate the sensor instead of course).

[madships]

Ah got you. Thought it was the ecu that did the heavy lifting r.e. signal conversion so expected the raw voltage to still be visible. Makes sense now.

[TimH]

Canbus not fast enough to transmit enough voltage samples to allow a meaningful analysis of the speed sensor signal.