Advanced Search

I believe you; I understand your problem too.
You could try measuring the voltages at the DIR pin (which can be held at a constant level) and comparing them.
Better still, use an oscilloscope to see how steep the edges are.
Otherwise, I’m out of ideas.

Using a Mesa7i92 + 74hc245 (5V) + dm542 (unmodified dir input pc817), the zero-point return is correct and without error. This is why I raised the issue of the Riocore + Tang Nano9k + 74hc245 (5V) + dm542 (unmodified dir input pc817) failing to return to zero.

I’d guess that with the Mesa card, the voltage is slightly higher than that of your level shifter, which produces a more stable pulse.
It must be right on the limit, as some pulses get through and some don’t; even 0.2 volts could make the difference.
All in all, I’d recommend not using the drivers – not with Mesa, anyway – as the threshold is too close to the limit.
Or you’ll need to switch to 12/24V so that the driver is triggered reliably.

If you have a variable power supply, you could try increasing the voltage to 5.5 V and see if that helps; the level shifter should be able to cope with that.

viewsat wrote:

I'm showing four sets of drivers in the photos, but only this inexpensive DM542 has a problem

A long time ago, 3xTB6560 drivers were popular and I had them too.
There, PC817 supported not only dir inputs, but also step inputs. There were problems with this, but the chips were in sockets and it was easy to replace them with selected ones and it worked somehow.
So there are only two options:
1. Your driver is faulty.
2. This type of driver is poorly designed.
Either way, the cause is not to be found in riocore.

Those are cute!
Been watching BattleBots since they started wayyyyy back, robot wars or whatever they were called then, when the remote control was at 27MHz and everything was discrete electronics.
Unfortunately never had a chance at it, even now ...well 3 years ago i called anyone and everyone who has anything to do with electronic trying to rally them into starting this, failed miserably.
Keep at it, just building something that works at that weight range is difficult, i would rather do the 250 LBS ones as there are more options to push stuff way beyond their limits.

DIR use pc817 Error!


DIR modified 6N137 ok!!

spent the last year actually using my cnc, and not to make more cnc machines, my cousin kept asking me to do this fight robot league with her son in highschool, so we went to an event and it was pretty cool so we've been tryng to do it ever since.
its a 1lb weight class, so 454g. its pretty hard because everything is dumb, rc shit is dumb, the drone shit is dumb. i had to find the closest software thing to linuxcnc i could find but its still shit by comparison. i have to use all these dumb materials, and do so many operations and fixtures, i have to make dumb custom motors, and stupid rubber molds. i had to buy and use an M1.6 tap...
i learned how to anodize thought, and its pretty cool.

 but im having a good time, except i keep getting destroyed by teenagers with 3d printers


 
 
 
 

   

 

NWE post=348703 userid=46071Looking at the drawing, it seems to be missing 1 degree of freedom. Is this intentional? Or am I overlooking something?
 

I forgot to mention. I'm calculating the 6th axis as a dummy axis.

I used this inexpensive DM542 only for testing RioCore, not for an actual CNC machine tool. The circuit modifications are for technical discussion only, please don't mind. I'm showing four sets of drivers in the photos, but only this inexpensive DM542 has a problem, hence this discussion. Strangely, increasing the dirhold value doesn't solve the problem; I really can't understand this. However, this inexpensive DM542, when used with the same settings on a MESA7I92, shows no positioning error. This inexpensive DM542 was taken from my existing engraving machine for testing.
 I'm from Taipei, Taiwan
   

.bit is correct for 7I96

(.bin is for 7I96S)
 

If ethercat reports your six slaves, its properly installed. The next step is to build a xml file which lcec_configgen does the heavy lifting for and then configure then move on to the ini and hal files.

Hallo PCW,
du hast geschrieben:
"If you have a 7I96, it can support up to 4 MPG encoders directly on the isolated inputs
with the right firmware ( 7i96_inmd.bin )"
Was ist der Unterschied zwischen 7i96_inmd.bit und 7i96_inmd.bin? Wichtig sind für mich 2 Achsenencoder
und ein Spindelencoder.
MfG
Hans

You can simply update the firmware to what you need with mesaflash.

say:

mesaflash --device 7i96 --addr [card_ip_address] --write 7i96_inmd.bit --reload

Where 7i96_inmd.bit comes from 7i96.zip and [card_ip_address]  is either 192.168.1.121
or 10.10.10.10 depending on the 7I96 jumpering.


www.mesanet.com/software/parallel/7i96.zip

 

Hallo PCW,
ich habe die 7I96 vor ein paar Jahren gekauft. Wie kann ich feststellen ob die Firmware 7I96_inmd.bin installiert ist? Oder
ob da eine ältere oder andere installiert ist?

PC817 is a strange chip that works in a strange way.
First of all, it is an analog circuit, not a digital one.
Secondly, the input is controlled by current, not voltage, and the output forces current, not voltage.
In addition, the frequency response strongly depends on the input current, a small current means a small propagation time, but also a small output current.

Not really strange at all, almost all transistor/Darlington output optocouplers function this way
and this type optocoupler is by far the most common.

Logic optocouplers also typically have current inputs (since the input  of most optocouplers   is simply a bare LED)
but differ in having a voltage output.