Problem with delay DIR-STEP

Nikolay81 · Posted at 2018-8-10 14:38:58

ytliu Posted at 2018-8-10 07:22
The current motor drive signal generation logic is: in each signal processing period (t), the DIR si ...

Please cancel the order DM556.
Do not waste your money. You can not buy the same driver as mine.
If you can not cancel the order, I'll pay you. Just tell me how much it cost.
The problem is not only in DM556. Leadshine produces a huge number of driver models.
In addition, now most of their products are counterfeits (say 70%).
It is necessary, that the controller correctly worked with any drivers, and not only with 556.

In addition to removing the resistors and removing the oscillograms, yesterday I went to a company that has been repairing CNC machines for many years.
I asked their specialists to consult me for money, but they did it for free, for which I am very grateful.

They read our correspondence with you and explained the problem. We were both mistaken.
Everything is simple enough. Briefly, it is necessary to increase the delay "DIR-STEP" to 7000-10000 nanoseconds.
Then any drivers will work correctly with DDCSV.
You can partially bypass the problem, individually in the case of each specific driver.
But, only the correct delay DIR-STEP will make it so that there will be no problem at all.
With any drivers.

If you can not do this programmatically, you can hardware shift the signal STEP relative to DIR.
The simplest option is to install a circuit from the resistor and the capacitor between the driver and the controller.
It's a little bit ugly in the form of the signal, but as I saw yesterday, the optocoupler, it's still very ugly.

Today I will write an article in which I will describe in detail what they explained to me.

Please do nothing until you read the article. You also need to understand what is going on to solve the problem.

Nikolay81 · Posted at 2018-8-11 01:14:07

Last edited by Nikolay81 In 2018-8-13 03:41 Editor

ytliu Posted at 2018-8-10 07:22
The current motor drive signal generation logic is: in each signal processing period (t), the DIR si ...

I wrote a new article for you.
I hope it will help you better understand the reasons for missing the steps and find a good solution.
This problem is quite difficult to understand. Perhaps machine translation will distort the meaning of some phrases.
But I'd better do it until I can.
Please read the article and tell us your opinion about it.

https://drive.google.com/open?id ... 9uvzhUmf3IJdtMNvpR_

ytliu · Posted at 2018-8-11 06:24:11

Nikolay81 Posted at 2018-8-11 01:14
I wrote a new article for you.
I hope it will help you better understand the reasons for missing t ...

Thank you very much for your analysis of this issue, I will use the first way you said to make changes.

Nikolay81 · Posted at 2018-8-11 14:47:19

Last edited by Nikolay81 In 2018-8-11 15:03 Editor

ytliu Posted at 2018-8-11 06:24
Thank you very much for your analysis of this issue, I will use the first way you said to make cha ...

Thank you, for your desire to solve the problem, dear Ytliu.
I understand that solving this problem is quite difficult for you.
Making changes to hardware logic can cause many other glitches.
I certainly do not ask you to solve the problem, right now.
In such cases, you can not hurry.
It is necessary to think everything over.
You can solve this problem in six months, or a year.

The main thing is that now DDCSV, a little "crippled" or "problem" controller.
Since it does not meet the specifications of the leading manufacturer of drivers.

And the solution to this problem will immediately bring DDCSV to a whole new level of quality and reliability.
It will be possible to raise the price for it.
For example, now I would not risk, sell a lot of DDCSV, like your dealer.
Because, by reason of technical problems with the product, this business can "eat" me later.
To earn good money, i need to sell at least 40 controllers a month.
This is 500 controllers a year.
If even 10% of buyers have a hard-to-solve problem with the loss of steps, I will spare all my free time, I will spend on technical support of users.
But life is too short to waste it so stupidly :-)
I ask you to understand my position.
Have a nice weekend.

Mehmet · Posted at 2018-8-12 00:28:37

Dear ytliu and nikolay
First of all. Thank you for a lot efforts for find a good solution about a problem. Everyday I am following your posts.
I am learning a lot of things from your posts (systems, stepper drive, signal ,step-dır, step lose etc...)

I am a simple DDCNC 2.1 user , but i don't have a cnc. I need a lot of parts like stepper driver, screws, spinle ..For now, I have a DDCNC 2.1 controller.
I want to make cloosed loop cnc so , next week order a Lichuan closed stepper driver. If you are use closed loop step (with encoder) never losing step ?  Is it correct ?
I am not sure but Lichuan stepper driver's Logic input current : 10 mA at 60vDC @200kHz  Ia=(5V-0.7V)/(270+100)=11.6ma > 10mA. (formula from ytliu). is it ok. for controller dncnc?

I need your experiences, If i use this closed loop  driver , machine doesn't lose steps when fast changing direction. I it correct or not?
Should I use a pulley belt system for solve  torque , microstepping , step loses.

http://servo.xlichuan.com/prod_v ... 166&FId=t3:69:3

Soory for my english.I hose so you understand..

alexwalex · Posted at 2018-8-12 02:08:05

Last edited by alexwalex In 2018-8-13 00:40 Editor

Mehmet, i use this drivers and he does not lose steps. I tested parameter #416=50 with 1920 pulse/mm and no have a problem. Maybe dear ytliu have more information.

Nikolay81 · Posted at 2018-8-12 07:51:33

Mehmet Posted at 2018-8-12 00:28
Dear ytliu and nikolay
First of all. Thank you for a lot efforts for find a good solution about a pr ...

This is a good driver.
Use Falling-Low, # 416 = 2000, dividing step 1/16. And almost certainly, there will not be any loss of steps.
Although the manufacturer also indicates a minimum delay of DIR-STEP of 5 microseconds.
No additional resistors, do not put.
It is desirable to properly configure the antiresonance in the driver.

Nikolay81 · Posted at 2018-8-14 18:06:16

While Ytliu tries (or does not try) to implement the delay of DIR-STEP programmatically, I'll try to do it in hardware.
Of course, this is not an ideal option. But if you do not get it programmatically, there will be a backup option.
DDCSV is a very good controller. I believe that he has great prospects.
It's a pity that due to this flaw, it can not work with many drivers.

There are already a few options for implementing a digital delay line.
I think, within a week, it will be possible to make preliminary samples.
In any case, I will achieve the solution of this problem, since these controllers are very interesting for me.

ugv · Posted at 2018-8-14 19:15:07

why you don't install the old ver:2016-06-29-81NOR ? work well we can change the time beetween pulse and dir

ugv · Posted at 2018-8-14 19:40:03

i can send you install files by mail if you want

Problem with delay DIR-STEP

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