HEIDENHAIN TNC 122 Technical Manual - Manual (Page 17)

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TNC 122 9 Machine Integration 4/97
9 Machine Integration
9.1 Encoders
You can continue to use the same incremental position feedback encoders on the TNC 122, as you
used on the TNC 121.
Signal period
The signal period of the linear encoder is entered in machine parameter MP330.x (in
µ
m). On linear
encoders with sinusoidal output signals, the signal period is the same as the grating period:
Signal period (~) = Grating period
The standard linear encoders from HEIDENHAIN have a grating period of 20 µm. Older encoders
have a grating period of 40 µm.
If linear position feedback is carried out with a rotary encoder on the ballscrew, then to calculate the
signal period you must consider not only the line count of the encoder (see the technical data for the
encoder) but also the pitch of the ballscrew:
Signal period (~) =
Screw pitch [mm] · 1000 [
µ
m/mm]
Line count
MP330
Signal period
Input values: 4, 10, 20, 40, 100, 200 [
µ
m]
MP330.0 Axis 1
MP330.1 Axis 2
MP330.2 Axis 3
Machine parameter MP7320 can set the encoder amplitude so that older encoder models (on
machines with TNC 121) can be adapted to the TNC 122.
MP7320
Switchover of encoder input amplitude
Input values: 0 to 7
Bit 0 Axis X +0 = 16 µA
+1 = 40 µA
Bit 1 Axis Y +0 = 16 µA
+2 = 40 µA
Bit 2 Axis Z +0 = 16 µA
+4 = 40 µA