HEIDENHAIN TNC 407 (243 020) Technical Manual - Manual (Page 190)

01.98
TNC 407/TNC 415/TNC 425 3 Servo positioning of the NC-axes 4-65
4
3 Servo positioning of the NC-axes
This section describes all the control functions which are important for the control and monitoring of
the NC-axes .
Further parameters for the NC-axes can be found under "Machine axes".
The control of the main spindle (S-axis) is described under "Main spindle".
3.1 The position control loop of an NC-machine
In CNC machines the servo control is normally implemented as a cascade control (see following
block diagram).
The motor speed control and the current control (both in the drive amplifier) are integrated into the
servo position control (CNC-control). The servo controlled system consists of the motor and machine
slide.
A
c
tual
rpm A
c
tual
position
Linear/
angle
encoder
Speed
controller
Position
controller
Current
regulator
Drive Tacho
Nom.
cur.
Nom.
pos.
Servo
lag
Nom.
rpm
A
c
tual
cur
rent
A
c
tual
position A
c
tual
rpm
CNC Control Servo amplifier Machine
Block diagram of the position control loop, here as a cascade control