HEIDENHAIN TNC 306 Technical Manual - Manual (Page 355)

3/2000
TNC 416/TNC 406/TNC 306 Commands 7-65
3.5.4 LESS THAN OR EQUAL TO (<=) <=
Abbreviation for the PLC-Editor: <= (LESS EQUAL)
Byte/Word/Double Constant
Execution time [µs] 1.8 to 2.4 1.8 to 2.0
Number of bytes 6 8
Operands: B, W, D, K
Operation:
With this command, a direct transfer from Word to Logic processing occurs. The contents of the
Word Accumulator are compared with the contents of the addressed operand. If the Word
Accumulator is less than or equal to the operand, the condition is true and the Logic Accumulator is
set to 1. If the Word Accumulator is greater than the operand, the Logic Accumulator is set to 0. The
comparison takes place over the number of bits in the operand, i.e. B = 8 bit, W = 16 bit and D = K
= 32 bit.
Example:
A constant is to be compared with the contents of Double word D8. The result is then assigned to
Marker M500.
Initial state: Constant = 16 000
Double word D8 = 15 000
The Accumulator and operand contents are shown in decimal notation. The 10 bit wide Accumulator
allows the entry of the highest possible Accumulator contents (2 147 483 647).
Line Instruction Accumulator contents Operand contents
x x x x x x x x x x
1 L K16000 1 6 0 0 0
Bit 31 . . . 7 0
1 <= D8 ... x x x x x x 0 x x x x x x x 1 5 0 0 0
2 = M500 ... x x x x x x 0 x x x x x x x 0
Line 1: The constant is loaded into the Accumulator.
Line 2: The contents of the Accumulator and the Operand are compared (Accumulator <=
Operand). As this condition is not fulfilled the Logic Accumulator is set to 0.
Line 3: The contents of the Logic Accumulator (The result of the comparison) are
assigned to Marker M500.