Lichuan "Easy Servo" closed loop stepper question

[Voicecoil]

Just wondering if anyone has any knowledge of these please as I'm not getting a reply to my question from the factory.... There's an "alarm" output on the LCDA2575 driver module - does anyone know what this does in terms of function i.e. when it switches, and what is the max voltage it can switch? I have a data sheet which came with the motors, but it makes very little mention of this output.
Thanks

[Doddy]

http://www.t2cnc.hu/downloads/Lichuan/LCDA257S%20English%20User%20Manual.pdf suggests the output is simply the C/E of an optocoupler. Without knowledge of the part number of the opto you could make an educated guess based on common devices - most seem to have a Vceo of 60V upwards.

...of course you could always take one apart to check?

[m_c]

I'd probably go for 24VDC and 20mA being a safe limit.

And given it's very likely a Leadshine copy/clone, and having checked some similar Leadshine drives, their usual output is 24VDC but with current limits varying between 20-80mA.

[Voicecoil]

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[Voicecoil]

http://www.t2cnc.hu/downloads/Lichuan/LCDA257S%20English%20User%20Manual.pdf suggests the output is simply the C/E of an optocoupler. Without knowledge of the part number of the opto you could make an educated guess based on common devices - most seem to have a Vceo of 60V upwards.

...of course you could always take one apart to check?

Looking inside I can see a little white (hence likely an opto) 4 pin device adjacent the pins, but like most SMD's it doesn't have the device number, just some cryptic code on it :grumpy:

24V/20ma is a good guess, but there's still the issue of what does it indicate....

[m_c]

Looking inside I can see a little white (hence likely an opto) 4 pin device adjacent the pins, but like most SMD's it doesn't have the device number, just some cryptic code on it :grumpy:

24V/20ma is a good guess, but there's still the issue of what does it indicate....

Something wrong? :barbershop_quartet_

I'd guess it'll depend on all what the driver is capable off, and what settings can be changed via software.
Motor/wiring problem (does the drive sense motor wiring issues?), motor following error (there's a parameter for it...).
Have you got a copy of the 'simple commissioning manual' that's mentioned below the parameter table?

[Voicecoil]

Something wrong? :barbershop_quartet_

Have you got a copy of the 'simple commissioning manual' that's mentioned below the parameter table?

No, sadly not, all that came with the parts is the manual Doddy put up the link to. I've tried emailing them again, but this time it bounced straight back - I wonder if they've gone under? - though their website is still up and running.

[the great waldo]

I don`t know if this will help, it's a link to their product page
http://servo.xlichuan.com/prod_view.aspx?TypeId=69&Id=177&FId=t3:69:3

Cheers
Andrew

[Voicecoil]

Well, by chance I came across this page:
https://www.omc-stepperonline.com/closed-loop-stepper-driver/closed-loop-stepper-driver-0-70a-24-48vdc-for-nema-17-23-24-stepper-motor-cl57t.html
These drivers seem to be mechanically and electrically identical to the LIchuan parts other than the paint colour, branding and slightly smaller supply voltage range - if anyone has one of these it would be interesting to remove the cover and compare the PCB with the Lichuan part, I have a suspicion that they will be very similar knowing how things happen in China!. And there's a manual full of all sorts of good info you can download, and which has a very interesting typo in the last paragraph of page 5 :redface:

[the great waldo]

Well, by chance I came across this page:
https://www.omc-stepperonline.com/closed-loop-stepper-driver/closed-loop-stepper-driver-0-70a-24-48vdc-for-nema-17-23-24-stepper-motor-cl57t.html
These drivers seem to be mechanically and electrically identical to the LIchuan parts other than the paint colour, branding and slightly smaller supply voltage range - if anyone has one of these it would be interesting to remove the cover and compare the PCB with the Lichuan part, I have a suspicion that they will be very similar knowing how things happen in China!. And there's a manual full of all sorts of good info you can download, and which has a very interesting typo in the last paragraph of page 5 :redface:
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 by the way if you order these as kits don't forget they come with cables, I didn't notice that and ordered some cables from their Belgian site. Oh well i'm sure i'll find a use for the wire or plugs

[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.
26485

[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-Micro-International-CT185GB-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

Andrew2649126492

[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 :rolleyes: