No +5V to outputs?

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06-26-2019, 04:57 AM
Yastron

No +5V to outputs?

I'm doing a servo conversion on my stepper router and am completely stuck with getting the servo to spin (just X axis for now).

I have Mach3, and AKZ250 USB smoothstepper, and the servo I am trying to install is a Teknic Clearpath SDSK

My stepper setup never had any outputs, but now that I'm going to servos I need to use an output to enable the stepper.

My problem as I see it is this:
If, under outputs, Enable1 is enabled and set to pin 4, and if I hit "RESET" in Mach3 so that the diagnostics page light "Enable1" is activated, then I should be able to use a voltmeter and read +5V from output 4 to ground, right?
I tried toggling all the activelows, checked all the output pins, nothing I tried will allow me to read +5V at the output pins. Am I looking at this the right way? What am I missing ? How do I get an output to read +5V

Thanks for any help, much appreciated
06-26-2019, 05:22 AM
CitizenOfDreams

Re: No +5V to outputs?

Your board, like most of them, has open collector outputs. To read 5V, you need a pull-up resistor between the output and the +5 bus.
06-27-2019, 01:53 AM
Yastron

Re: No +5V to outputs?

Quote:

Originally Posted by CitizenOfDreams

Your board, like most of them, has open collector outputs. To read 5V, you need a pull-up resistor between the output and the +5 bus.

Thanks very much citizen that's definitely it... Sorry I am a total noob. I got the servo running now, much appreciated.

For now I just put the enable pins straight to +5V and Ground, so the motor is always enabled when it is connected to my laptop, is there anything wrong with that until I buy a resistor?
06-27-2019, 12:22 PM
CitizenOfDreams

Re: No +5V to outputs?

Quote:

Originally Posted by Yastron

For now I just put the enable pins straight to +5V and Ground, so the motor is always enabled when it is connected to my laptop, is there anything wrong with that until I buy a resistor?

The drawback is that the servos will not be disabled when you push the E-stop button.

Do you really need a separate pull-up resistor? Your servo input may already have it, try connecting it directly to the board output.
06-28-2019, 05:36 AM
Yastron

Quote:

Originally Posted by CitizenOfDreams

The drawback is that the servos will not be disabled when you push the E-stop button.

Do you really need a separate pull-up resistor? Your servo input may already have it, try connecting it directly to the board output.

Having the servo enable+ wire connected directly to the board output yielded no +5V to the enable pin, which is my original issue.