Re: home switch on stb4100
That will indicate the stb4100 input terminal is connected to the +24V via a resistor and the LED inside the opti-isolator as in the last photo in post 2
most of the missing 2V will be the forward volt drop across the LED
That means you can connect the proximity sensor directly to the stb4100 input terminal
when the proximity sensor switches on the NPN transistor will ground the stb4100 input terminal to the -24V supply
and I would expect a current of about 10mA will flow out of the stb4100 input terminal and to ground via the proximity sensor
you can check this by connecting a stb4100 input terminal to ground via a meter set to the 200mA range
John
Re: home switch on stb4100
so i was worried about burning up the board for no reason i can connect it to the breakout board directly without doing any harm and don't need to drop voltage any the board with handle the voltage ?
Re: home switch on stb4100
yes, this time
with other breakout boards or motion controllers designed to work at 5V logic levels it could of been different
without any detailed information thats why I wanted to know what the stb4100 input open circuit voltage was
now we know both the stb4100 input circuit and the proximity sensor both work at 24V levels
you can connect them together
John
Re: home switch on stb4100
thanks you john for your understanding and patience i do appreciate the help and information
1 Attachment(s)
Re: home switch on stb4100
thank you
as long as you have your machine working
this is what you should have when the proximity sensor is connected to a stb4100 input
Attachment 427040
without your measurements I could not be sure there was not a voltage regulator reducing the +24V to a lower voltage to power the opto-isolators
John
Re: home switch on stb4100
i have another question i hooked up the proximity sensor and its 20.6 and it drops down to .62 when its flagged but my question is on the breakout board it says there should be 0-10v at the dac and common part do you think it needs to be hooked up to the vfd to initiate the volt flow ? it also hook to the start and stop for the spindle?
1 Attachment(s)
Re: home switch on stb4100
Once mach3 is setup and sending a PWM signal to the DAC (digital to analogue converter)
you should see the 0 to 10V control voltage between the DAC and COM terminals
Attachment 427076
I have not found a high resolution photos to reverse engineer the board to be sure the COM and -V terminals are isolated or connected together
but from this photo you can see the +V connection goes via a diode that prevents damage if the 24V supply connections are reversed
( the diode can be seen in the bottom left hand corner )
In general board follows the design pattern followed by many breakout boards
Having what I expect to be a ULN2801 transistor array in a socket is a great advantage
the IC can easily replaced if you short circuit the +24V to one of the 4 outputs
A week ago I replaced a damaged FET in a AXBB motion controller
see posts 39 & 40
AXBB charge pump fault - Page 4
John