C Code

[Borgix]

I tried all evening to find how to read the current value for the x, y, and z axis. I'm sure it's something very simple, but even though I'm perfectly capable of moving each axis, I can't get the value (in machine coordinates).

Any hint?

thanks,
B.

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[TomKerekes]

Hi B,

The Commanded Destination for axis 0 is ch0->Dest

The Measured Position for axis 0 is ch0->Position (only valid if you have feedback)

See KMotionDef.h for the definitions of all the Axis Channel Parameters

You might also look at the PrintFollowErr.c example:

#include "KMotionDef.h"

main()
{
    double vx,vy,speed;
    for (;;)
    {
        Delay_sec(0.5);
        WaitNextTimeSlice();  // ensure we don't get interrupted
	vx = (ch0->Dest - ch0->last_dest) * (1.0f/TIMEBASE);
        vy = (ch1->Dest - ch1->last_dest) * (1.0f/TIMEBASE);
	printf("speed = %f %f cnts/sec Err = %12.0f %12.0f %12.0f cnts\n",
			vx,vy,
			ch0->LastFollowingError,
			ch1->LastFollowingError,
			ch2->LastFollowingError);
    }
}

Regards

[Borgix]

axis 0 is ch0->Dest
ch0->Position (only valid if you have feedback)

thank you! I looked through the .h file and even found the channels (axis 0 - 8), but I didn't see the ch0->Dest and ch0->Position. where's the struct defintion for ch0?

I did

printf("Axis :\n\tx: %f\n\ty: %f\n\tz0: %f\n\tz1: %f\n", ch0->Dest, ch1->Dest, ch2->Dest, ch3->Dest);
printf("Axis :\n\tx: %f\n\ty: %f\n\tz0: %f\n\tz1: %f\n", ch0->Position, ch1->Position, ch2->Position, ch3->Position);

and got this output

Axis :
x: 17620.834697
y: 17620.834697
z0: -8852.938141
z1: -8836.988400
Axis :
x: 17620.800263
y: 17620.834697
z0: -8852.938141
z1: -8836.988400

The current machine coordinates are
X:4.3347
Y:2.8302
Z0:-0.5523
z1:-0.5533

How do I get to the machine positions from the chx->Dest numbers?

[TomKerekes]

Hi B,

where's the struct defintion for ch0?

see the CHAN structure definition

How do I get to the machine positions from the chx->Dest numbers?

Divide by your system's resolution in counts/unit

HTH
Regards

[Borgix]

Divide by your system's resolution in counts/unit

Duh! Sorry for not seeing this myself. I had even gotten the Axis resolution, but it didn't make sense even dividing it, because I didn't realize that I have 2 channels for x What I assumed is y was the 2nd x motor. Works like a charm!

Axis Resolutions Found:
x: 4065.040039
y: 2540.004883
z: 16000.000000
DEST Axis :
x1: 4.000000
x2: 4.000000
y: 4.999976
z1: -0.553309



z2: -1.000000