HEIDENHAIN ITNC 530 - CONVERSATIONAL PROGRAMMING User Manual page 469

Selection of alternate tilting possibilities: SEQ +/– (entry
optional)
The orientation you define for the machining plane is used by the TNC
to calculate the appropriate positioning of the rotary axes present on
the machine. In general there are always two solution possibilities.
Use the SEQ switch to specify which possibility the TNC should use:
SEQ+ positions the master axis so that it assumes a positive angle.
The master axis is the 2nd rotary axis from the table, or the 1st axis
from the tool (depending on the machine configuration (see figure at
top right).
SEQ- positions the master axis so that it assumes a negative angle.
If the solution you chose with SEQ is not within the machine's range of
traverse, the TNC displays the Entered angle not permitted error
message.
When the PLANE AXIS function is used, the SEQ switch is
nonfunctional.
If you do not define SEQ, the TNC determines the solution as follows:
1 The TNC first checks whether both solution possibilities are within
the traverse range of the rotary axes.
2 If they are, then the TNC selects the shortest possible solution.
3 If only one solution is within the traverse range, the TNC selects
this solution.
4 If neither solution is within the traverse range, the TNC displays
the Entered angle not permitted error message.
HEIDENHAIN iTNC 530 469