MoTeC Global Forum

Im facing a strange issue. I m getting a 12 volt output from all of my digital inputs! I have nothing connected on Connector A and i still get 12v out when monitoring it from pdm manager! This happens on 2 pdms that i tried. Again nothing else connected on any pin other than 12v supply, gnd and can bus. Any idea what might be wrong??

I don't think anything is wrong. The PDM User Manual says all switch inputs have a 10k pull-up resistor to Batt+, so you would expect to see 12v on any switch input that is not switched to ground.

Yr right thanks . So how can i use switch to high if its permanent high....?

Hi,

I'm assuming that you have an input that is switching with Battery voltage, so when the input is off it will be seeing 0v and when it is On it will see VBatt? If this is the case, then you set the Input Type to be Active High and adjust the triggers so that they work through the range of the switching voltage.

I did all that but since the input always has 12v on its own (even with nothing connected to it) , then it always sees the input as active even if my 12v switch is off. should i use a pull up resistor? how do i wire it please?
thank you

No, you would add a pull-down resistor if you want the signal to read zero volts when the switch is off. Be aware this will leak current when the PDM is off however.

Are you switching the inputs with actual switches, or with the output/s of something else?
How many switch inputs do you want to use?