China Servo Driver

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Bordaco
Posts: 3
Joined: Wed May 15, 2019 12:55 am

China Servo Driver

Post by Bordaco » Thu May 16, 2019 4:25 am

A year a go, I change the control to an old VMC (German made, Haidenhain TC.... controller) with Kflop+Kanalog+Konnect, it work really well, original drivers and motors, for the 3 axis and spindle.
A few weeks a go, the Z motor overheated, so i bought a Chinese AC servo motor 2.6kw, with break, i asked for a velocity control mode driver with a 0 to 10 =/- volt signal and encoder feedback, but the one o got, only accept positive 0 to 10vdc signal, and a change direction bit on the i/o port.
So i need help to configure the system to control this driver, any options??, by a separate c program? will coordinated motion use this program?
Thanks in advance.

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TomKerekes
Posts: 2529
Joined: Mon Dec 04, 2017 1:49 am

Re: China Servo Driver

Post by TomKerekes » Thu May 16, 2019 4:23 pm

Hi Bordaco,

You will need a small C Program to write the Servo Output in a Sign and Magnitude manner to a DAC and direction bit. This will be similar to writing to a PWM in Sign and direction mode. See the article here.

Instead of writing to the FPGA to control the PWM write to a DAC using the syntax:

DAC(channel, value);

where value is a integer +/-2047 counts.

HTH
Regards,

Tom Kerekes
Dynomotion, Inc.

Moray
Posts: 282
Joined: Thu Apr 26, 2018 10:16 pm

Re: China Servo Driver

Post by Moray » Thu May 16, 2019 6:39 pm

What make of servo did you get?
Or do you have a link to the one you bought?

Bordaco
Posts: 3
Joined: Wed May 15, 2019 12:55 am

Re: China Servo Driver

Post by Bordaco » Fri May 17, 2019 7:01 pm

Servo motor a driver brand Lichuan, AC servo 3ph 220v 2.6kw, 2500 rpm, 10Nm, 10A.

Bordaco
Posts: 3
Joined: Wed May 15, 2019 12:55 am

Re: China Servo Driver

Post by Bordaco » Fri May 17, 2019 7:09 pm

Hello Tom,
Ok, thanks, but still in the clouds, :roll: , in a program loop forever, capture the value of DAC 2 and check if is positive or negative, then if is negative, convert to positive, turn on the direction bit and output the value through another DAC chanel connected to the driver , can do this the job??

Moray
Posts: 282
Joined: Thu Apr 26, 2018 10:16 pm

Re: China Servo Driver

Post by Moray » Fri May 17, 2019 9:13 pm

Bordaco wrote:
Fri May 17, 2019 7:01 pm
Servo motor a driver brand Lichuan, AC servo 3ph 220v 2.6kw, 2500 rpm, 10Nm, 10A.
I suspected as much. It's a bit late now, but the other more common (and typically slightly more expensive) Chinese servo driver has full +/-10V capability.
One option available is to breakout a couple wires from the RJ cable linking the KFlop to Kanalog, and run the servo in step/dir or CW/CCW mode.


If you want to use analogue mode, then here's the code I use for my lathe spindle, which uses 0-10V and one of two bits to select direction -

Code: Select all

// **** Start Spindle Control ****
		// As the standard channel output options can't handle activating outputs depending on
		// direction required, this takes the output from channel 2(Spindle), and activates them
		// accordingly
		if(ch2->Enable)
		{
			if(ch2->Output > 0)
			{
				SetBit(153);
				DAC(2,(int)ch2->Output*-1);
				
			} else {
				ClearBit(153);
			}
			if(ch2->Output < 0)
			{
				SetBit(154);
				DAC(2,(int)ch2->Output);
			} else {
				ClearBit(154);
			}
		} else {
			ClearBit(153);
			ClearBit(154);
		}
		// **** End Spindle Control ****
		

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