need help about DSPMC/IP controller

[jelwaan]

I want to use DSPMC/IP controller and I need some help,

I have an old flame cutting machine ( 2 axis - BLDC motors ), this machine is controlled with an old controller , It is used to cut steel palns.

I want to replace this old controller with a new Computer based controller, and I found the DSPMC/IP controller sutable since it can controlled through the ethernet ( the machine is 2m * 8m and I want to controll it from the upper floor).

I want to Interface this controller to the motors, and need help :

what kind of encoders to use with this DC motor, Or I can control them with out encoder (I have two tachoMeters)?

I have made a H-bridge PWM DC Driver befor, Can I use it to control this motors through DSPMC/IP or I should buy a specific Driver?

Can I use EMC2 to control the DSPMC/IP Or I should use Mach3?

What model of DSPMC/IP I should use to control just two DC motors?

Thanks

[Al_The_Man]

How are the motors being controlled now? If you have a servo system in place there has to be encoders present, you cannot position with Tach's.
Are they DCBL or DC brushed?
Al.

[bharbour]

That DSPMC/IP controller is a pretty interesting looking little controller. It's motor interface is a +/-10Volt signal. You will need to convert that to a brushless DC drive to use the motors that you have. There are many drivers available for this commercially. Look up "Variable Speed Brushless Drive".

A brushless DC motor is really a lot more like a 3 phase AC motor than a DC motor. It has 3 sets of windings and sensors to detect what position the motor shaft is in for commutating the drive signals. Old ones used Hall effect sensors, I think newer ones are optical, but they are still commonly called hall sensor signals. You will need 3 half bridge drivers for the coils and logic to commutate the drive signals. I have seen a number of micro-controllers designed for driving brushless DC motors. The control input would be an A/D converter on the +/-10V signal. It would be a significant hardware and software project to build this driver I think. Based on this, I would buy a drive if you want this running this year.

If the old controller is a servo system, there will be encoders already in the system somewhere. They are likely on the motors themselves. If not, you can add encoders to the motors if there is any shaft available on the back side of the motor. You probably want what is called a quadrature optical encoder. They are available with several output configurations, my recommendation would be to get the ones with differential output for noise reduction. Also, the controller supports it. Another choice will be the "pulses per revolution" rating on the encoder. That will have to be chosen based on the gear reduction in the mechanical drive system and the easurement resolution you want. Note that the resolution you get is usually 4X the "pulses per revolution" value of the encoder. As Al said, you will have to have encoders in the system somewhere to run servos.

Good Luck,
BobH

[jelwaan]

many thanks,