HEIDENHAIN TNC 640 (34059x-01) ISO programming - Manual (Page 276)

276 Programming: Q Parameters
8.1
1
Pr
eassigned Q P
a
ra
met
e
rs 8.11 Preassigned Q Parameters
The Q parameters Q100 to Q199 are assigned values by the TNC. The
following types of information are assigned to Q parameters:
„ Values from the PLC
„ Tool and spindle data
„ Data on operating status
„ Results of measurements from touch probe cycles etc.
The TNC saves the values for the preassigned Q parameters Q108,
Q114 and Q115 to Q117 in the unit of measure used by the active
program.
Values from the PLC: Q100 to Q107
The TNC uses the parameters Q100 to Q107 to transfer values from
the PLC to an NC program.
Active tool radius: Q108
The active value of the tool radius is assigned to Q108. Q108 is
calculated from:
„ Tool radius R (tool table or G99 block)
„ Delta value DR from the tool table
„ Delta value DR from the T block
Do not use preassigned Q parameters (or QS parameters)
between Q100 and Q199 (QS100 and QS199) as calculation
parameters in NC programs. Otherwise you might receive
undesired results.
The TNC remembers the current tool radius even if the
power is interrupted.