HEIDENHAIN TNC 306 Technical Manual - Manual (Page 360)

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TNC 416/TNC 406/TNC 306 Commands 3/2000
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.