HEIDENHAIN PROFIBUS-DP (DPV2) - Manual (Page 76)

Functionality in the PROFIBUS DPV2 device
76
B. Non-cyclic operation
If the desired total measuring range is not equal to the specified
single turn resolution * 2X (where x<= 12) the encoder operates
in non-cyclic operation. The non-cyclic operation is affected by the
parameter G1_XIST 1 Preset control as described below.
G1_XIST1 Preset control=Enabled
If the position value increases or decreases outside the maximum
value or below 0 with the parameter G1_XIST 1 Preset control
enabled, the device outputs the maximum position value within
the scaled total range for both position values G1_XIST 1 and
G1_XIST 2.
Example of non-cyclic scaling with G1_XIST 1 Preset control
enabled:
Total measuring range= Measuring units per revolution x number
of revolutions
Measuring units per revolution = 100
Number of revolutions= 50
(=50 is not equal to 2X where x<=12 means that a non cyclic
scaling will be used)
Total measuring range = 100 x 50 = 5000
Figure 23 Non-cyclic scaling G1_XIST 1 Preset control enabled