1 f undamentals – HEIDENHAIN TNC 320 (340 55x-05) Cycle programming User Manual
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Touch Probe Cycles: Automatic Datum Setting
15.1 F
undamentals
Saving the calculated datum
In all cycles for datum setting you can use the input parameters Q303 
and Q305 to define how the TNC is to save the calculated datum:
Q305 = 0, Q303 = any value
The TNC sets the calculated datum in the display. The new datum is 
active immediately. At the same time, the TNC saves the datum set 
in the display by the cycle in line 0 of the preset table.
Q305 not equal to 0, Q303 = –1
Q305 not equal to 0, Q303 = 0
The TNC writes the calculated datum in the active datum table. The 
reference system is the active workpiece coordinate system. The 
value of parameter Q305 determines the datum number. Activate 
the datum with Cycle 7 in the part program.
Q305 not equal to 0, Q303 = 1
The TNC writes the calculated datum in the preset table. The 
reference system is the machine coordinate system (REF 
coordinates). The value of parameter Q305 determines the preset 
number. Activate the preset with Cycle 247 in the part program.
Measurement results in Q parameters
The TNC saves the measurement results of the respective touch 
probe cycle in the globally effective Q parameters Q150 to Q160. You 
can use these parameters in your program. Note the table of result 
parameters listed with every cycle description.
This combination can only occur if you
read in programs containing Cycles 410 to 418 created 
on a TNC 4xx
read in programs containing Cycles 410 to 418 created 
with an older software version on an iTNC 530
did not specifically define the measured-value transfer 
with parameter Q303 when defining the cycle.
In these cases the TNC outputs an error message, since 
the complete handling of REF-referenced datum tables 
has changed. You must define a measured-value transfer 
yourself with parameter Q303.
