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I believe I have just about everything I need figured out on our double gang grinder CNC lathe conversion as far as operation goes.. The only thing I have yet to figure is altering the position of the where the marker starts on the preview grid. I would really like to have the plot marker in preview to be in the middle of the X on the grid. Tool offset and home offset have had zero change to the position marker's start on the grid. 
Thanks in advance.

Hi, I work as a CNC Plasma Beam line Operator and any time I change consumables I have to reset the number of hit of the plasma to zero and as is cutting it count the number of hit, and know how long the consumables last and to change them can't we do the same thing to QtPlasmaC.

It does make the resolution of the encoder frequency  a bit better than at 1 ms
but the periodm does not care as you specify the number of period averages.

scotta wrote:

Hi, which module have you been trying to use? The software Encoder module or the QDC module? Both support the index pulse detection and encoder count latching so LinuxCNC can acquire the index position count.
 

Hi.
QDC.
The encoder_raw code is good and there are only hardware problems (optocouplers and RC filters cut the bandwith).
But this is very bad idea to send encoder's index pulse by ethernet.
Let's make calculations.
3000 rpm and 1 ms base_thread is 18 degrees accuracy - not acceptable.
The solution is send not index, but raw_count lathed at encoder's index edge interrupt routine.
There is in your code, line 321 in qdc.cpp file:But there is no indexCount hal pin...
In the fact, we don't need receive index pulse at component side, because change of indexCount means index was betwen last and present data transmision.
So we can update indexCount at every encoder's index edge, but use them only if hal index_enable pin is true. (look at my code).

I tried use raw_count and index pins connected to PRUencoder module. Sometimes it works, mostly not.
But even if it works, PRUencoder resets position to zero at received index, not at real index.
In my code, position is reset not to zero, but to(raw_encoder may be not equal latched_enc)
So there is no delay.
In this case I not need PRUencoder, because I move pos and vel calculations to my component. 

Thanks for the info. From what I gather, reading previous posts, the periodm function requires linuxcnc 2.10. I'll have to make up another test unit for that. Also, I'm running a 2msec servo thread. Is that going to be an issue?

None of these are needed and the first will likely mean
that you never get an index.

setp [HMOT](CARD0).encoder.00.index-mask 1
setp [HMOT](CARD0).encoder.00.index-invert 0
setp [HMOT](CARD0).encoder.00.index-mask-invert 0

The index mask logic is intended for configurations
that have a index mask input pin which is typically used
for spindles where the encoder is on the motor and the
spindle is geared down from the motor.
 

The reed switch works great. Thanks for everyones help.

What are the joint and axis MIN_LIMIT values in your .ini file for Z?

When  HOME = 0,  MAX_LIMIT  should be greater than 0, to avoid get stoped by softlimit error

Hi, which module have you been trying to use? The software Encoder module or the QDC module? Both support the index pulse detection and encoder count latching so LinuxCNC can acquire the index position count.

There are a few issues. Should we break them into new threads?

1. The discussed issue about being on or over a limit. The resolution/variance comments.
2. Axis UI will allow an AXIS to be moved back within limits, but Probe Basic does not
3. The docs state: "The [JOINT_N]MIN_LIMIT/MAX_LIMIT settings are enforced while jogging in joint mode prior to homing. After homing, [AXIS_L]MIN_LIMIT/MAX_LIMIT coordinate limits are used as constraints for axis (coordinate letter) jogging" but that is not the case. This is different for Probe Basic and Axis.
3a. Using the Axis UI, the JOINT MAX_LIMIT and MIN_LIMIT are ignored before homed, meaning no limits are enforced.
3b. Probe Basic seems to enforce the AXIS_L limit, whether homed or not

  The velocity range only seems to be around 6500 hz from 0-10mm (3/8")

That does seem quite small, maybe too much stray capacitance on the sensor?

The BCL-AMPs ~2.5 MHz /2 frequency of ~1.25 MHz only gives you about 1250
counts per 1 ms servo period which will end up adding quite a bit of noise.
 This may be improved if you set the hires-timestamp of the encoder true but
a better solution may to use the periodm's frequency output as it does frequency
estimation by 1/period_average:

forum.linuxcnc.org/plasma-laser/51568-in...e-sensor-to-linuxcnc

Is there a home switch on the Z axis?

Rember that you can touch-off an axis.

So G0 Z0 ≠ "Go to actual, physical 0 coordinate"

Sometimes LinuxCNC is weird.

Look at the stepconf default config and try to make your config similar if you can.

Worked for me!