Duet 3 Expansion 1HCL tacho reading

[matej1006]

Hello can i connect two tacho readings to Duet 3 Expansion 1HCL or i can change any input to tacho reading?

[dc42]

@matej1006 you can use io0_in and io1_Iin as tacho inputs for fans connected to the OUT ports.

[matej1006]

@dc42 One other question please can i use this cabel for can-FD comm. J‑Y(ST)Y 2x2x0,8 I can't find any other cable in Slovenia.

[oliof]

@matej1006 I am using random 0.15mm dia wires for CAN-FD comm, just twisting the wires. So 0.8mm dia should work fine. If you want to use the other two leads for power, 0.8mm is roughly ok for up to 6A, so should be fine as well.

[matej1006]

@oliof would lenght of 1.5m to 2m any problem to stable comm.

[oliof]

@matej1006 I ran up to a meter, but I don't think that 2m are a problem if you use shielded wires or twist them or add a ferrite bead to avoid noise.

[matej1006]

@oliof i think that wires aren't twisted but whole cable is shielded with aluminium foil

[dc42]

@matej1006 this would be better if you can find it https://www.thomann.de/gb/sommer_cable_quantum_highflex_multipair_2.htm. However, for a cable length of only 2m the type of cable is not critical.

[matej1006]

@dc42 can I use OUT 0 and OUT 1 on tisti same board for PWM controlling my noctua fans and water pump. Will be same as fan pwm output?

[dc42]

@matej1006 yes you can, provided the current they require doesn't exceed the rating of the outputs. Check the water pump starting current in particular.

[matej1006]

@dc42 it is a 12V pc Water colling so i think it will be ok but i will check just to be sure about it

[matej1006]

@dc42 if i connect 12v directly from power supply tacho won't work ?

[dc42]

@matej1006 tacho connections should still work of you connect the positive fan wire direct to +12V.

[matej1006]

@dc42 this is how have now connected all . And pump won't start! GND is commom

[dc42]

@matej1006 have you the specification of the pump?

You may need to invert the polarity of the out port in the M950 command, as you would for a PWM fan.

[matej1006]

@dc42 it is 12Vdc 17W pump which can be connected directly to pc Mother board
I did try to invert and pullup and nothing was different

[dc42]

@matej1006 does the pump work if you disconnect the blue PWM wire?

[matej1006]

@dc42

; Water colling PUMP
M950 F2 C"!Fan0" Q25000 										; fan 2 is a 4-wire PWM fan so invert it, use high PWM frequency, tacho connected to PB6 on expansion connector
M106 P2 H5 I1 T20:25 L255                                       ; set fan 2 value. Thermostatic control is turned on

This is my code from duet2 eth board
Now I have duet3 6hc
I try same code and it wasn't work

If I swap noctua fans with pump fans works on this output out6 pump on out5 is same nothing from her

That I didn't try I Will tommorow