HEIDENHAIN TNC 335 Technical Manual - Manual (Page 450)

8/95
TNC 360 3 Commands 7-71
3.6.5 EXCLUSIVE OR [ ] (XO[ ]) XO[ ]
Abbreviation for PLC Editor: XO[ ] (EXCL: OR [ ])
Logic Byte/Word/Double
Execution time [µs] 2.0 3.2
Number of bytes 6 6
Operands: none
3.6.6 EXCLUSIVE OR NOT [ ] (XON[ ]) XON[ ]
Abbreviation for PLC Editor: XON[ ] (EXCL: OR NOT [ ])
Logic Byte/Word/Double
Execution time [µs] 2.4 3.8
Number of bytes 8 8
Operands: none
Function of Parentheses with Logic Commands:
The execution sequence in a ladder may be altered by the use of parentheses. The "open
parentheses" command loads the contents of the Accumulator onto the Program Stack. If the Logic
Accumulator is addressed in the previous command, prior to a "parentheses open" instruction, the
content of the Logic Accumulator is loaded into the Program Stack. By addressing the Word
Accumulator, the content of the Word Accumulator will be distributed.
The "close parentheses" instruction initiates the gating of the buffered value from the Program Stack
with the Logic Accumulator and/or the Word Accumulator, depending on which Accumulator was
addressed prior to the "parentheses open" instruction. The result is then available in the
corresponding Accumulator. The maximum nesting level is 16 parentheses.