How do I override the limit switches?

[Lotreck]

]Hello. For my machine you need 10 limit switches.
For this I wanted to use I/O 26-35.

ch4->LimitSwitchNegBit=32;              //32-00100000
ch4->LimitSwitchPosBit=33;            //33-00100001

Does not work. Why?
I/O 12-13 is working.
How do I override the limit switches?

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[TomKerekes]

Hi Lotreck,

How did you interface the switches?

How did you configure the Limit Options?

Take care not to drive any KFLOP IO above 3.8V.

Did you test to see if the Inputs change on the Digital IO Screen when activated?

To override Limits set the Limits Options to zero (turn off Watch Limit options). See:
Configuration Screen

Regards

[Al_The_Man]

]Hello. For my machine you need 10 limit switches.
how do I override the limit switches?

What is the function of the switches? Over travel?
Why the need to input them all?
Al.

[Lotreck]

The switch is an inductive sensor connected via an optocoupler board with a pull-up resistor.

If I use such a connection scheme, then everything works fine.

[CODE#include "KMotionDef.h"

main()
{
ch4->InputMode=NO_INPUT_MODE;
ch4->OutputMode=STEP_DIR_MODE;
ch4->Vel=40000.000000;
ch4->Accel=400000.000000;
ch4->Jerk=4000000.000000;
ch4->P=1;
ch4->I=0.010000;
ch4->D=0.000000;
ch4->FFAccel=0.000000;
ch4->FFVel=0.000000;
ch4->MaxI=200.000000;
ch4->MaxErr=1000000.000000;
ch4->MaxOutput=200.000000;
ch4->DeadBandGain=1.000000;
ch4->DeadBandRange=0.000000;
ch4->InputChan0=0;
ch4->InputChan1=0;
ch4->OutputChan0=4;
ch4->OutputChan1=0;
ch4->MasterAxis=-1;
ch4->LimitSwitchOptions=0xD0C001F; //00001101 00001100 00000000 00011111
ch4->LimitSwitchNegBit=12; //12-00001100
ch4->LimitSwitchPosBit=13; //13-00001101
ch4->InputGain0=1.000000;
ch4->InputGain1=1.000000;
ch4->InputOffset0=0.000000;
ch4->InputOffset1=0.000000;
ch4->invDistPerCycle=1.000000;
ch4->Lead=0.000000;
ch4->MaxFollowingError=1000000000.000000;
ch4->StepperAmplitude=20.000000;


ch4->iir[0].B0=1;
ch4->iir[0].B1=0;
ch4->iir[0].B2=0;
ch4->iir[0].A1=0;
ch4->iir[0].A2=0;


ch4->iir[1].B0=1;
ch4->iir[1].B1=0;
ch4->iir[1].B2=0;
ch4->iir[1].A2=0;


ch4->iir[2].B0=1;
ch4->iir[2].B1=0;
ch4->iir[2].B2=0;
ch4->iir[2].A1=0;
ch4->iir[2].A2=0;
EnableAxisDest(4,0); //
DefineCoordSystem(-1,-1,-1,4); //


return 0;
}


][/CODE]

And if this, then when you press the move button, the axis is deactivated, the color turns yellow.


[CODEch4->LimitSwitchOptions=0x2120001F; //00100001 00100000 00000000 00011111ch4->LimitSwitchNegBit=32; //32-00100000
ch4->LimitSwitchPosBit=33; //33-00100001][/CODE]

[TomKerekes]

Hi Lotrek,

Thanks for the clear information.

The first 8 IO on JP4 and JP6 have 150 ohm pull down resistors. See:
KFLOP Connectors

So the 1Kohm pull up resistor to 3.3V will only provide:

3.3V x 150 / (1000 + 150) = 0.43V

You could verify this with a voltmeter.

If the transistor can conduct 16ma you might do something like:



But I see your optocoupler board probably connects all the emitters together to the same pin. Is that your design?

IO34 and IO35 do not have the 150ohm pull down resistors. But they do have a weaker pull down option. It is actually more of a constant current sink of between 0.1 - 0.75ma. Changing the opto coupler resistor to ~3K and connecting it to 5V should work for those 2 inputs.

Or you could use a Konnect

HTH
Regards

[mlinkadelsol]

Hi Lotreck,

How did you interface the switches?

How did you configure the Limit Options?

Take care not to drive any KFLOP IO above 3.8V.

Did you test to see if the Inputs change on the Digital IO Screen when activated?

To override Limits set the Limits Options to zero (turn off Watch Limit options). See:
Configuration Screen

Regards

Hi Tom, what is the best option to disable limit/homing switch watching after the machine is homed? I am getting HF spindle noise and would like to disable the switches when machine is cutting so I dont get interruptions in the middle of the job.

[TomKerekes]

Hi Lotrek,

It would be better to eliminate the noise.

But to disable limits see my previous post.

ch0->LimitSwitchOptions=0x0;