Lichuan "Easy Servo" closed loop stepper question

[Voicecoil]

Hi Voicecoil
The cl57t run with up to 8 amps. I think they are made by leadshine. I have 3 on order at the present time. I'll pop one open when they arrive if it's not to difficult and post a photo.
cheers
Andrew

Here's a pic of the Lichuan board.

[Doddy]

Interesting...

The photo is almost good enough - but I can't quite make out the marking on the mid opto - it looks like the one on the right - a 6N137, but I can't quite squint hard enough to read the markings. If it is, then I'd be convinced that all three opto devices are inputs (the 137's being the Pulse/Dir inputs and rated at 10MHz, the CT185 being the cheaper/slower ENABLE input. I can't see any other opto devices. What gives me pause for thought are the 4 SMD diodes next to these (I'd expect 3, for input protection to the optos). Which begs the question, where are the ALM outputs connected??

Can you check visually the 4-pin opto (https://datasheet.lcsc.com/szlcsc/CT...T1_C191836.pdf) - if pin 1&2 head towards the green connector then this is the ENABLE input, which is what I expect. The alternative is the middle opto (who's number I can't read) is not a 6n137 but instead a two-channel opto for the slower DIR/ENA inputs.

If the 4-pin device pins 1/2 do head to the green connector then my worry is that the ALM outputs are not opto-isolated but an open-drain output from the DSP. If this is the case then I'd be very cautious of how to connect these.

If the 4-pin device pins 3/4, instead, head to the green connector then the link above describes the characteristics of the output switching capability.

The data sheet for the driver does suggest the alarm output is derived from the encoder/position error detection.

[Voicecoil]

That other DIP8 opto is also a 6N137, makes sense as although DIR won't change state as often as PULSE, there are setup times to be observed. Visual checking of the little white iso-optalator proved fruitless (hidden tracks) so I resorted to a DMM to bleep it through, and it appears to be connected to the enable input, albeit via a resistor or two. Peering underneath the board however there's another one however which I imagine does the alarm output, both those pins show >2Meg to ground, so are likely floating.

[Doddy]

Peering underneath the board however there's another one however which I imagine does the alarm output, both those pins show >2Meg to ground, so are likely floating.

Crafty buggers. Well, that answers your question as to the output drive capability.

[the great waldo]

Hello chaps
Here are a couple of photos of the stepperonline cl57T closed loop driver made by guess who. I hope its of interest. I got the kit with the nema 24 4nm motors the price difference with the 3 nm motor wasn't much and i'll be interested to get the machine together as i've had it lying around for months and am still using my old makko 850 machine with acme threads which makes horrible noises when pushed a bit.
cheers

Andrew

[Voicecoil]

Thanks for that Andrew, the boards look pretty well identical apart from a couple of current sense resistors which are shorted out on the OMC - it would be interesting to know who copied who