HEIDENHAIN MANUALPLUS 620 - 6.18.2 Spindle in position feedback control

1000 HEIDENHAIN Technical Manual MANUALplus 620
6.18.2 Spindle in position feedback control
Position encoder of
the spindle
Analog and digital spindles can be driven in a closed position control loop. In
this case the spindle needs its own position encoder, or you use the speed
encoder to measure the position of a digital spindle.
Due to the higher required accuracy, the position encoder should be mounted
directly on the spindle.
 Enter the encoder model for position measurement in
MP_posEncoderType.
 Enter the value 360 in MP_posEncoderDist.
 Enter the line count of the encoder being used in MP_posEncoderIncr.
1V
PP
signals undergo 1024-fold subdivision.
 Enter the value 360 in MP_distPerMotorTurn.
If the position encoder cannot be mounted to the spindle because of its
design, the encoder will output several reference pulses per revolution. For
example, with a transmission of 4:1 (motor to spindle), you will receive four
reference pulses (every 90°) per spindle revolution.
 Define the position encoder-to-spindle transmission ratio in
MP_distPerMotorTurn, for example:
MP_distPerMotorTurn = = 90
Set MP_externRefPulse = spindleRef to use an external reference pulse
input (X30 or –REF.SP) as reference signal. The reference mark of the position
encoder will not be evaluated in this case, see page 1008.
 Evaluate the reference mark with Module 9220 (see "Renewed traversing of
the reference marks" on page 793).
The individual gear ranges are realized via one spindle parameter set each, see
"Gear shifting" on page 1567.
In NN_SpiReferenceAvailable, the NC reports whether the reference
position of the spindle has been determined.
PLC operand / Description Ty p e
NN_SpiReferenceAvailable
Reference position found
0: Reference position not found
1: Reference position found
M
PP_SpiReferenceMarkSignal
Trip dog
0: Trip dog not triggered
1: Trip dog triggered
M
360
4
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