I solved the Problem You have to PullUp the Pin than it will work.

Depending on the current needed you can use both options and still draw the power from the external 12v supply. Both the fan and heater output is switched on the low side, so you can wire the LED+ to your 12V supply and the LED- to the - of either the fan or heater output and have it work just the same. A inline fuse is always a good idea when you're circumventing the Duets fuse, other than that LEDd don't require any safety precautions.

I solved it, didnt read enough... The Duex5 inverts the signal depending on how you name the pin in firmware... The spam bot wont let me change the first post anymore I guess "Sometimes a pin has multiple names. Example: "exp.heater3" "exp.8" "duex.e2_heat" "duex.pwm1" These four all refer to the heater3 pin, either on the expansion connector (where it is pin #8 of 50) or on the heater output terminal block of a DueX2 or DueX5. However, there is a difference. The DueX boards buffer and invert the signal. Therefore, when you use one of the forms prefixed with duex the firmware knows it has to invert the signal, but it doesn't invert it if you use one of the other forms. In contrast, when you referred to logical pin 3 in previous versions of RRF, the firmware always inverted the signal - so if you were driving a servo or BLTouch from this pin you would have needed to use the I1 parameter in your M280 command."

It's already mentioned at https://duet3d.dozuki.com/Wiki/Duex_wiring_diagrams#Section_Warnings_and_Cautions.

Thanks for the quick response. I made a couple of test leads and measured a good 3.3V between the 3.3V, TWD, and gnd. However when I measured TWC, twice, it registered only 136mV. The Duex5 has been swapped and although much longer than the provided ribbon cable, I had an old 50 pin SCSI cable which I tried with the same negative result. So I assume that would point to a problem with the Duet-wifi card. Thanks

@bearer Thanks for the info. Added and moved a jumper, powered on and nothing went bang or started smoking. Just need to wire my LEDs now and test again. Thanks again. Paul.

It's a typo, it should say E2-E6 heaters, not E2-E7.

@flux said in Connect servo motor to Duet2Wifi with Duex5: i can use a servo OR a heater, but don't booth a same time on a same channel? Correct.

@dc42 it fixed the issue with RC4