user785: I have a servo motor with following specs
Torque - 1.08Nm
Max rpm - 3000
Current rating - 7.8 amp
Max voltage - 56V DC
Please tell me how to calculate whether an arduino board - uno rev 3 can control the servo motor? If not, how to find out how many such boards are required?

user136: The optical encoder you link to has 500 pulses per revolution. This means at 3000rpm , you will be generating pulses 25,000 times a second. You will also need to deal with overshoot (as there is nothing worse than a motor going overspeed and the feedback loop being unable to detect it).
Dealing with an optical encoder generating pulses this quickly is actually quite a challenge, especially with Arduino (which has rather slow native I/O using digitalRead and digitalWrite), and the ATmega328 (which doesn't have any dedicated hardware to deal with high speed optical encoders).
Driving a 56VDC, 7.8A motor isn't an easy challenge either - a motor driver for this isn't going to be easy to design.
I'd probably look for a dedicated servo or CNC motor controller to deal with something like this.

user37: An Uno most definitely cannot directly control that motor. According to the specs here,

They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA

So your motor has needs about ten times the voltage and 200 times the amps that the Uno can supply. Of course, you can always get a driver of some sort for the servo.

785: <p>I have a servo motor with following specs
Torque - 1.08Nm
Max rpm - 3000
Current rating - 7.8 amp
Max voltage - 56V DC</p>

<p>Please tell me how to calculate whether an arduino board - uno rev 3 can control the servo motor? If not, how to find out how many such boards are required?</p>
 136: <p>The optical encoder you link to has 500 pulses per revolution. This means at 3000rpm , you will be generating pulses 25,000 times a second. You will also need to deal with overshoot (as there is nothing worse than a motor going overspeed and the feedback loop being unable to detect it).</p>

<p>Dealing with an optical encoder generating pulses this quickly is actually quite a challenge, especially with Arduino (which has rather slow native I/O using digitalRead and digitalWrite), and the ATmega328 (which doesn't have any dedicated hardware to deal with high speed optical encoders).</p>

<p>Driving a 56VDC, 7.8A motor isn't an easy challenge either - a motor driver for this isn't going to be easy to design.</p>

<p>I'd probably look for a dedicated servo or CNC motor controller to deal with something like this.</p>
 37: <p>An Uno most definitely cannot directly control that motor. According to the specs <a href="http://arduino.cc/en/Main/ArduinoBoardUno" rel="nofollow">here</a>,</p>

<blockquote>
  <p>They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA</p>
</blockquote>

<p>So your motor has needs about ten times the voltage and <em>200</em> times the amps that the Uno can supply. Of course, you can always get a driver of some sort for the servo.</p>
