HEIDENHAIN TNC 306 Technical Manual - Manual (Page 330)

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TNC 416/TNC 406/TNC 306 Commands 3/2000
3.2.3 SET NOT (SN) SN
Abbreviation for the PLC-Editor: SN (SET NOT)
Operand changed Operand unchanged
Execution time [µs] 2.0 to 2.4 1.0 to 1.4
Number of bytes 8 ( 6 )
Byte value in parentheses:
With certain preceding program sequences the command may be shortened.
Operands: M, I, O, T, C
Operation:
The function of the command is dependent upon the contents of the Logic Accumulator. If the Logic
Accumulator = 0 , then the addressed operand is set to 1, otherwise the operand remains
unchanged. An SN command is used at the end of a logic chain, in order that a gating result may
influence the operand. The command may be used several times in succession (see example).
Example:
Input I4 and Input I5 are to be gated with OR.
If the gating result = 0, Output O2 and Marker M500 are set.
Initial state: Input I4 = 0
Input I5 = 0
Output O2 = ?
Marker M500 = ?
Line Instruction Accumulator Contents Operand Contents
Bit 31 . . . 7 0
... x x x x x x X x x x x x x x
1 L I4 ... x x x x x x 0 x x x x x x x 0
2 O I5 ... x x x x x x 0 x x x x x x x 0
3 SN O2 ... x x x x x x 0 x x x x x x x 1
4 SN M500 ... x x x x x x 0 x x x x x x x 1
Line 1: The operand contents are loaded into the Accumulator.
Line 2: The contents of the Logic Accumulator and Input I5 are gated with OR.
Line 3: The gating result = 0: Output O2 is set.
Line 4: The gating result = 0: Marker 500 is set.