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Author Topic: Pokeys 57E Encoder reset  (Read 3071 times)

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Pokeys 57E Encoder reset
« on: September 05, 2015, 09:00:03 AM »
I have hit a brick wall here and in desperate need of help

I am driving my lathe tool turret with a small stepper motor. The turret rapid rotates (47deg) anticlockwise past location, pawl engages then slowly rotates (2 deg) clockwise to locate etc.

I have got it working physically in that I press a button and  it indexes properly. However as a safety feature I have added an encoder to verify that it has indexed correctly.

(eventually I want to get it working automatically via  M6 macro)

I have linked the turret rotation up to A axis and that DRO is working fine. I have created a encoder count DRO  and that is mimicking the values in the Pokeys F7 table  but what I can't

get it to do is to zero. Note if I press the reset button on the F7 table it does zero but not via my macro.

What I want to achieve is the following. (encoder related only)

When the button is pressed the macro is called.
The encoder count is set to zero.
When the turret rotation is complete the encoder count value is compared with a reference value.
If it is within range proceed, if not output an error message and stop.

For the moment I have cleaned the macro down to just two lines

DoOEMButton(1011)  ' This zeros the A axis DRO and this works'   I have left this in as this proves my link from the button to the macro works

SetOEMDRO(102,0)  ' This isn't working


For information

The encoder is set up as encoder 2 in pokeys mapped to OEM DRO 102 " MPG2" and setup in config ports and pins encoders

(Also don't know if it's relevant but I am not using pokeys pulse engine)

I am pulling my hair out here so any help would be greatly appreciated

cheer George

Offline NeoTO

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Re: Pokeys 57E Encoder reset
« Reply #1 on: September 05, 2015, 10:53:48 AM »
Hi, George

Encoders are handled in the PoKeys device itself and the plugin merely forwards the values to Mach3. It is not possible to set the encoder value from Mach3.

Since you are not using MPGs for jogging, you can assign the encoder value to an unused DRO slot and handle the resetting in your script.
www.poscope.com home of PoKeys USB HID, IO, USB, Ethernet controler and PoScope USB PC oscilloscope
Re: Pokeys 57E Encoder reset
« Reply #2 on: September 05, 2015, 12:27:07 PM »
Hi NeoTO

Many thanks for your help

I have changed the DRO used to 1999 to both Pokeys encoder DRO, and dro box via screen4

then using SetOEMDRO(1999,0) in macro

and I am just getting the same result

ie the values are in the DRO box and moving with the motor but still won't reset

Can you see what I am doing wrong?

cheers George

Offline NeoTO

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Re: Pokeys 57E Encoder reset
« Reply #3 on: September 05, 2015, 01:11:54 PM »
Instead of setting DRO to zero, save the current value of the DRO in your own variable. This is offset that you subtract from encoder DRO to get your new position, which you can save to a new DRO.

So, for example, you determine that the encoder value of 1234 should be showing 0. Save 1234 to a offset variable and subtract this value from then on. The encoder value of 1244 will then read +10.
www.poscope.com home of PoKeys USB HID, IO, USB, Ethernet controler and PoScope USB PC oscilloscope
Re: Pokeys 57E Encoder reset
« Reply #4 on: September 05, 2015, 01:33:59 PM »
Hi NeoTO

Cracked it (I Think)

I set Pokeys Encoder2 DRO setting to 102  'MPG2"

Then did a short one line brain program


(ADD Input)    Mach variable  MPG2 count

(ADD Input)   No Operation

(Terminate)    DRO 1999


This just copies the values from DRO 102 to DRO 1999

then in script

SetOEMDRO(1999,0)

and it works (or seems to so far) the only thing I think I need to

check is what the transfer rate is like in real time to make sure of it's repeatability.

If it introduces too many errors I will do what you say and tweak in script.

Many Many thanks for all your help (On a Saturday Too !!!!!)

cheers George
Re: Pokeys 57E Encoder reset
« Reply #5 on: September 06, 2015, 05:51:32 AM »
Spoke too soon,  It doesn't work

The values are copied from DRO 102  to DRO 1999

and you can reset DRO 1999

but when turret starts moving again the values don't start from

zero and count up they just copy DRO 102    Obvious when you think about it

Hey Ho  I will do it as NeoTO suggested and subtract start value in script

cheers George