HEIDENHAIN iTNC 530 Service Manual page 110

Principle of
operation of
iTNC530
Nominal and actual The position controller receives its nominal value, e.g., from the NC program; the actual value
values for the is normally provided by a linear encoder (scale). The actual position value can also be provided
controllers by a motor encoder instead of a scale. The position of the machine table depending on the
number of counting pulses or revolutions of the motor encoder is set in the machine parameters
(e.g., one revolution of the encoder changes the table position by 10 mm).
The speed controller receives its nominal value from the position encoder. Thus the output
quantity of the position controller is the input quantity of the speed controller. This is why this
interface is also designated as "nominal speed value interface". With analog axes, the control
leads the nominal speed value interface (± 10V) "outside" to the analog servo amplifier. With
digital axes, this interface is "inside" the control!
The actual value for the speed controller is supplied by the motor encoder.
The current controller receives its nominal value from the speed controller. The actual value is
provided by current sensors in the power module.
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