Help needed: 7i77 with Heidenhain linear encoder and EXE602E

Hello Guys,

I'm actually working on getting my Deckel FP4A back to work.

I wired everything up and made a basic configuration with the help of Pncconf, what worked fine for me.
For the main tasks, I'm using the following setup: 5i25 - 7i77isol - 7i77.
The basic things are working fine (Inputs / Outputs), but I have problems with my Heidenhain linear encoders - described as below:The factory-mounted Heidenhain linear encoders are connected with a Heidenhain EXE602E, the internal jumpers there are setted to 1 & 3 open, the others closed (according to the data-sheed, posted in an other thread Heidenhain EXE-602 Configuration )
The EXE is connected with the 7i77s Encoder plug (TB3) in the following manner:
           7i77 - EXE

• QA0 - Ua1
• /QA0 - /Ua1
• GND - 0V/GND
• QB0 - Ua2
• /QB0 - /Ua2
• +5V - Up/+5V
• IDX0 - Ua0
• /IDX0 - /Ua0

The encoder is set to 1000 counts/mm.

My problem is, that it seems that the 7i77 can't read any signal - or better to say: Nothing is displayed while running LinuxCNC.

I searched the forum a lot, but was unable to find some solution. I allready checked, whether the cards TB3 GND and +5V are short-cutted, but they aren't.
The only thing I found is, that I can't meassure 5V between these pins, but ~0,5V - even with an unplugged encoder.

The described issue can be found at all three axis!

Am I missing something ? Is my 7i77 faulty ?

Thank you for your help and best regards from Germany,
Simon
 

Do you have an Osci? Can you see the square wave out of the EXE when you move the encoder? I used a couple of those stand alone 602 EXE's on my Maho. Have you provided the 7i77 with an independant 5v PSU and jumpered for it, or is it receiving 5V through the cable from the 5i25?

The current draw of three EXE#s exceeds the current the 5i25 can supply.
Mark

Hello Mark,

thank you for your quick answer!

Yeah, I do have an old tube-osci. You mean, just supply +5V and GND to the EXE and watch Ua1 and /Ua1 or Ua2 and /Ua2 on the osci?

Due to the lack of a DIN-Rail 5V power-supply (it's stuck in the Mail...), I actually use a laboratory power-supply with adjustable Ampere. Due to the use of the 7i77ISOL between 5i25 and 7i77, both cards need to be jumpered to cable-power but with external 5V supply for the 7i77 to power the 7i77ISOL. The laboratory supply shows slightly below 1 Amp with one 7i77 and one 7i64.
I allready thought about powering the EXE directly and not through the 7i77s encoder plug.
The 5V supplied by the laboratory supply are pretty accurate - I've read something about +-5% currency-tollerance for the EXE.

Regards,
Simon

P.S. Mark, can you meassure the currency, supplied by the 7i77 at the encoder-plugs while no encoder is plugged in? I wonder, why I only can meassure 0,5V there

Do you read 0.5V with no EXE connected?
It might be possible that the 7I77's PTC tripped
with 3 EXEs connected.

Hello PCW,

at least with one EXE... I was stupid and didn't meassure the voltage wit no EXE connected... I'll meassure it this afternoon.
Do you think, I should power the EXE directly with 5V or will this affect the 7i77.

Regards,
Simon

Hello Guys,

I just tried out something:
7i77 + 7i64 without ecoders or other 5V consumers plugged in: 0,9A
Measured voltage between 7i77 TB3 GND & +5V: 5V

This leads to the presumption, that the EXEs Power-consumption is much higher than the 7i77 is able to supply.
Now, the next logical step to me is to power the EXEs directly from the same power-source than the 7i77. There should be no risk to damage anything, am I right ?

Regards,
Simon
 

Should be fine (even separate supplies is OK as long as they share a common ground)

Hello PCW,

Thank you a lot for your help !
I'll try it within the next few days and keep you updated

regards,
Simon

Hello together,

yesterday, I made some further tries...

I directly powered up the EXE and encoder with my laboratory supply, but found that even with 2A (short time), the output voltage is still below 1V!

After that, I only powered up the EXE with the encoder unplugged, but the issue was still there.

The Cable is wired up according to Heidenhains manual with Pin 12 & 2 and 11 & 10 bridged.
As I mentioned a few days ago, the internal jumpers there are set to 1 & 3 open, the others closed.

I opened up the EXE to check, whether there is a heated part, but everything's fine...

Maybe, you know about this issue and can make a suggestion...
I'll also try to get some information from Heidenhain.

Thanks and regards,
Simon

Happy evening Update:

My X-Axis encoder is working !

After work, I called Heidenhain and talked with an very friendly technician there. He told me to doubble check my wiring, especially the pining of the plug - he once made the mistake to just soldereing the wires without checking the order of the pins - CW or CCW - and exactly this was my fault, also ! Such a stupid thing...

But I've got some more helpfull information from Heidenhain: The EXE602Es jumper setting:
1&2 closed: 5 fold interpoaltion
3 closed: reference pulse with 90° el
4 closed: High impendance on meassuring outputs
5 closed: /UaS >= 40ms

1&2 opened: without interpoaltion
3 opened: reference pulse with 270° el
4 opened: no High impendance on meassuring outputs
5 opened: /UaS >= 0,25ms

I'm very happy, to see a working axis, after all. But the other two encoders still aren't working... maybe I can check them tomorrow - I hope, there's nothing big...

Regards,
Simon

P.S. I've got the complete EXE602E manual from Heidenhain - just don't want to upload it due to copyright issues