(Solved) Index signal for Orient, G33.1, M19 with proximity sensor

Hello,
I'm trying to get rigid tapping to work.
My setup consists of a servo motor with encoder and a spindle. The trasmission is approx 1:1,64 with an GT 5 belt.
I want to get the index signal from an proximity sensor mounted on the spindle.

 

I followed talla's tutorials, but I failed on the input from the sensor in my hal file.

 

Does someone have experience in this sort of indexing an spindle?
Many thanks!
Best Regards Anton


 

It's relatively simple in principle, you just need to connect the encoder counter A and B to the servo encoder A and B, but connect the encoder index to the prox sensor rather than the index in the encoder.

And you need to get the encoder scale right."approx" 1:1.64 isn't good enough, you should use the exact ratio.

It seems that you are using a mesa card. What exactly are you not getting right? The config part or the actual wiring?

Are you using a 24v DC proxy ? PnP or NPN.?

If 24v, you need to be carefull because the encoder inputs on the mesa card can only handle 7v max I think so you need a level shifter between the proxy and the mesa card. A simple optocoupler IC should be fast enough, surely faster than the proxy.

Hello,
Many thanks for the quick reply!

I'm using a PNP NC sensor in 24v.
I've tried to connect the sensor to the mesa encoder input with a level shifter/stepdown to 5v (4,08). Then the encoder index was always on.
I'm using the Differential signals input of the mesa card, because with the ttl, i get no input from the servo driver.

Do i have to bridge the gnd of the encoder input to the indx - of the encoder?

Thanks!
Best regards and merry christmas Anton

There are jumpers to select differential/single for each of A B and Z encoder inputs. Try selecting single with the z jumper only. 

What type of level shifting have you used? 

There are jumpers to select differential/single for each of A B and Z encoder inputs. Try selecting single with the z jumper only. 

What type of level shifting have you used? 

Hello Henk,

I'l try to set the z input to single.
I used a voltage divider with two resistances. So the voltage is going from 24 to 5v(4,08v).

Could it be a problem whrn the signal is to long. Because the a and b signals are short and the index is longer.

Br anton

I don't think the length matters.

Can you verify the signal with a multimeter? If you can, switch back to differential and connect the 0v to the Z/ pin.
But make sure you don't apply more than 7v to the mesa encoder pins.

Also check that the signal goes low enough when connected, also try to reach 5 v when high. There is a certain hysteresis so low must be lower than a certain value

Hello Henk,

With a multimeter i got 4,08v when the sensor is triggerd and 0v when not closed.

I think a have to solder a new divider which reaches 5v

Br anton

As Henk says, you need to jumper the index input for single ended mode.

Also 4.08V is fine for a high level because when the encoder inputs are set
for single ended mode, the input threshold is 1.65V.