Control by CNC

In the case of spindles, at a higher speed the limit as from when the measurement system no longer supplies any valid signals can be exceeded. The P-AXIS-00220 (vb_regelgrenze) parameter specifies as from which speed the position control loop is opened and a transition to the closed-loop control mode takes place. The actual values, which are defined via the following error depending on the specified rpm speed, are simulated automatically.

From the endless rotation situation, closed loop control is resumed automatically once the actual value drops below the control limit. However, the reference point is then lost. This is why referencing is necessary again before a positioning motion.

In the case of digital drive systems (e.g. SERCOS), closed-loop control and monitoring of the control limit take place in the drive.