E tìm được mấy cái này bác ợ, trên mach 4 vẫn còn delay như mach 3 thôi bác. Khá là khó chịu nhưng phải sống chung với lũ thôi
The ESS has a fixed amount of memory, and the controller frequency is a setting for how many motion positions per second there are, or how many times each second the velocity is sent from Mach 3 to the ESS. Having it output data faster means that if can buffer less data. If your system is running out of data, try slowing this down to a slower frequency so the SmoothStepper can go for longer periods of times between updates from the PC/Mach3.

4 kHz gives a buffer of 250 ms or 1/4 second: This provides a faster response to commands like feed hold, since it uses only a quarter second buffer. However, your PC needs to be able to supply the data transmissions to the SmoothStepper fast enough (newer PCs that are not low end, and that are running properly, can handle this). While this provides for a snappier response, it will not be reliable for all machines and you may experience run out of data errors.
2 kHz gives a buffer of 500 ms or 1/2 seconds.
1 kHz gives a buffer of 1000 ms or 1 seconds: This is the default value most machines should use.
500 Hz gives a buffer of 2000 ms or 2 seconds.
250 Hz gives a buffer of 4000 ms or 4 seconds: Slow PCs can run this speed, and with a 4 second data buffer, it will make it hard for them to run out of data. This setting will have the slowest change in velocities out of all the settings, but should still work just fine for most applications.
ESS Step 2 - General Tab:

On the “General” tab, you can:

1) Verify the IP address

2) Buffer Size (Almost always left at 0.18) :

A smaller buffer size is more responsive to Feed Hold commands and Feed Rate Override, but more sensitive to the ESS running out of data if your computer gets bogged down.
A larger buffer size (which translates to "longer"), is less likely to experience the ESS running out of data (in case Windows ignores Mach or the plugin for a while), but will take longer to respond to Feed Hold commands.
The buffer size should be small enough that you have good response to jog commands, feed hold, and feed rate override. I would start out small, and continue to increase it until the delay is noticeable and uncomfortable. Then back off to where it feels good.