Problem with delay DIR-STEP

ytliu

Nikolay81 Posted at 2018-8-7 14:11
Perhaps we do not understand each other well.
I will try to explain.
For Leadshine drivers, and for  ...

For this problem, I need your cooperation.

Let's first look at the CW / CCW mode, will there be a loss of steps?

Parameters #230-#233(command type) and #234-#237(DIR in CW/CCW mode) have been added to the configuration file. You can set the command type to CW/CCW mode, and set  the direction of movement of axis via #234-#237.

If the controller is in CW/CCW mode, configure the drive to the same mode.

Nikolay81

Perhaps we do not understand each other well.
I will try to explain.
For Leadshine drivers, and for many other drivers, the DIR signal must switch slightly earlier than the STEP signal.
I tried both STEP signal levels. Anyway, at a value of # 416 = 300ns, it loses its steps on the Leadshine 556 drivers when
change of direction. Because, the minimum delay between DIR and STEP should be at least 5000ns.
Only then, the steps are guaranteed not lost when changing direction.
It is a fact. See the screenshot of the instructions for DM556.
Also, here is a link to Purelogic's research.
http://wiki.purelogic.ru/index.p ... %B8_DIR_%D0%B2_PLCM
See the end of the article.
They found out that when STEP signal level is changed to low, the delay should be even greater. Up to 25000ns (!). Since the Leadshine drivers do not work correctly with low level STEP signals.
Can I not correctly understand the meaning of the "Time interval between DIR & pulse" setting?
In my opinion, it determines how much the DIR signal is generated before the STEP signal. This is necessary because the driver does not have time
in time to understand that the direction of movement has changed (see figure).
I am wrong?
In any case, the machine loses its steps at # 416 = 300 ns (with a change of direction). And at # 416 = 7000ns does not lose.
I tried STEP both high and low. It does not change anything. The problem is solved only by setting parameter # 416, more than 5000ns.
But there is a bug that I described.

ytliu

In addition, you can also change the pulse trigger definition of the drive to solve such problems.

ytliu

If there are losing steps when changing direction,you do not need to adjust parameter #416, you only need to change the definition of the pulse level of the relevant axis (#418-#421).

Parameter #416 is recommended to set 300ns.