Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

tecno
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22 Aug 2017 18:44 - 22 Aug 2017 18:45 #97890 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

HCT is TB3 ground

PSU 24V GND is connected to 7i76e = TB3 and encoder is connected to PSU GND

I assume 7i76E internal GND is all the same.

A/B channels work OK

Last edit: 22 Aug 2017 18:45 by tecno.

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PCW
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22 Aug 2017 18:50 #97891 by PCW

Replied by PCW on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

I assume 7i76E internal GND is all the same.

No, the field I/O section is completely isolated from the rest

A/B channels work OK

That may well happen with a missing ground

Can you see changes in the index pin in HAL if you ground TB3 pin 13?

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tecno
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22 Aug 2017 18:50 #97892 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

Yes

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tecno
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22 Aug 2017 19:20 #97895 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

Still same problem after moving encoder GND to HCT GND.

HCT works like a champ here in my lab, from 4.6V to 5.1V supplied to HCT.

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PCW
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22 Aug 2017 19:23 #97896 by PCW

Replied by PCW on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

I would measure the voltage on TB3 pin 13 with the 24V encoder INDEX high and low

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tecno
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22 Aug 2017 19:25 #97897 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

5V HCT output connected, but transitions are there when not connected to pin 13.

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tecno
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22 Aug 2017 19:26 #97898 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

Can this be something with the voltage divider? Have only 10K + 2K2 at home (maybe 1K8)

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tecno
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23 Aug 2017 12:18 #97915 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

So today I set up my old Oscilloscope to see what is going on here. 7i76E + encoder and 74HCT14N in between.

This is how it looks like before 74HCT14N

This is after 74HCT14N

And still no reaction in LCNC

Can you guys tell me what is wrong here? This is driving me nuts not getting a simple hookup to work.

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PCW
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23 Aug 2017 12:29 #97916 by PCW

Replied by PCW on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

I would not expect to see a reaction in linuxCNC's watch window since the duty cycle of index is so low

As mentioned before, the best way to test index is to "sets" the signal that conveys index_enable
true and see if its cleared when you pass the index position.

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tecno
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23 Aug 2017 12:37 #97919 by tecno

Replied by tecno on topic Help needed to get my 7i76E + 7i85S + 7i73 on my mill going.

What would the correct syntax be?

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