user5195: I am a newbie to Arduino.
What I am going to do is to change my roll to roll printer to flatbed printer.
Rather using print roller, I decided to move the bed from a stepper motor.I know how to run the stepper motor for specific distance using arduino.
So I need to cheat printer to think that its roller is working and media is going through it.But actually what I am going to do is to monitor the printer motor running or not from arduino input and if the printer motor is running stepper motor will turn or if motor stops stepper motor must stop.
What my problem is how can I read that the dc servo motor status? How would I need to wire arduino input to servo motor to get the status.
Please show me some light on this.Sorry if this is a newbie question.
Thank you. 

user5168: Do you need to check if it is stalled? Or simply running?
Either way, you could check the voltage with an analogue input, compare against a threshold (empirically set) & use that. Take the voltage reading from the non-commoned side of the motor, after any driver circuit.
If you want stalled, a small resistance would help, if just running then you could get away with a digital input.
If the voltages aren't matched then a resistance divider chain would be necessary.

user6194: I would definitely use an Opto-Isolator between the motor and the Arduino for these reasons.
You will have a problems with the grounds as the motor reverses.
The 24V supply.  If you get something slightly wrong then it will take out the Arduino and the PC connected to it.
The motor will generate large voltage spikes( circa 50..300Volts) under certain condions.  The Arduino and the PC connected to it will complain, but not for long!

5195: <p>I am a newbie to Arduino.</p>

<p>What I am going to do is to change my roll to roll printer to flatbed printer.
Rather using print roller, I decided to move the bed from a stepper motor.I know how to run the stepper motor for specific distance using arduino.</p>

<p>So I need to cheat printer to think that its roller is working and media is going through it.But actually what I am going to do is to monitor the printer motor running or not from arduino input and if the printer motor is running stepper motor will turn or if motor stops stepper motor must stop.</p>

<p>What my problem is how can I read that the dc servo motor status? How would I need to wire arduino input to servo motor to get the status.</p>

<p>Please show me some light on this.Sorry if this is a newbie question.</p>

<p>Thank you. </p>
 5168: <p>Do you need to check if it is stalled? Or simply running?</p>

<p>Either way, you could check the voltage with an analogue input, compare against a threshold (empirically set) &amp; use that. Take the voltage reading from the non-commoned side of the motor, after any driver circuit.</p>

<p>If you want stalled, a small resistance would help, if just running then you could get away with a digital input.</p>

<p>If the voltages aren't matched then a resistance divider chain would be necessary.</p>
 6194: <p>I would definitely use an Opto-Isolator between the motor and the Arduino for these reasons.</p>

<p>You will have a problems with the grounds as the motor reverses.
The 24V supply.  If you get something slightly wrong then it will take out the Arduino and the PC connected to it.
The motor will generate large voltage spikes( circa 50..300Volts) under certain condions.  The Arduino and the PC connected to it will complain, but not for long!</p>
