Control position and velocity of the motor

Hi, i want to control the position and the velocity of the drive motor by analog output 0-10 vdc or 4-20 ma by s7-1200, the machine has two motors the master and the slave, the slave has to follow the position and the velocity of the master, they have two incrementals encoder for the velocity and two inductives sensors for the position one per each, and i would know how to implement a pid to control the analog output with both conditions (position and velocity)

thanks

VICTORSJG

Hi, i want to control the position and the velocity of the drive motor by analog output 0-10 vdc or 4-20 ma by s7-1200, the machine has two motors the master and the slave, the slave has to follow the position and the velocity of the master, they have two incrementals encoder for the velocity and two inductives sensors for the position one per each, and i would know how to implement a pid to control the analog output with both conditions (position and velocity)

thanks

 Your analog output will control speed of both drives. I understand you can use your encoders feedback with PID to synchronize the two drives. I haven't been able to get PID to work at all and gave up on it for the time being.

Positioning an be implemented using high speed counters and possibly speed control to slow down the drives before stopping to increase positioning accuracy. They will not stop on a dime (actually they can but maybe not on a hair) but I do quite a lot of positioning using VFDs for applications that have a bit of tolerance.  The slower you can drive whatever it is you positioning the better the accuracy.

If you want examples split your search to three different tasks:

-PID

-Analog processing (Norm_X, Scale,Unscale)

-HSC (high speed counters).

And there are plenty of examples on the forums and siemens sites.

If you cant find them ask and I will dig out some links.

Why do you not use two technological objects. One Position controlled axis (master) and one synchronous axis (slave)

Sync the slave to the master and then start the master, the slave will follow.

You can give position or speed commands to the master axis.

Hello miami,

miami

Why do you not use two technological objects. One Position controlled axis (master) and one synchronous axis (slave)

   How is synchronous axis achieved in the S7-1200?

Thanks In Advance.

Mister T

Hello,

synchronized axes are only available in S7-1500. But if you use the technology objects in S7-1200 to handle the axes and if you use OB "MC_PreServo" to bring set value from master axis to slave axis, I think the handling of the axes will be a little bit easier...

Hello.

That is a nice idea you have there.

To further your suggestion - how would one go to compensate for the following errors that occur in both MASTER and SLAVE axis? My concern is rooted in keeping the process time of the servo OBs to a minimum?

TIA

New question published by VICTORSJG is split to a separate thread with the subject Control position and velocity of the motor with S7-1500.

Best regards
Jen_Moderator