2 load not (ln) – HEIDENHAIN TNC 407 (243 020) Technical Manual User Manual
Page 499
3.1.2 LOAD NOT (LN)
Abbreviation for the PLC-Editor:
LN (LOAD NOT)
Logic
Byte/Word
Double
Constant
Execution time [µs]
0.2 to 0.7
0.5 to 1.6
0.5 to 0.7
0.2 to 0.3
Number of bytes
6
8
6
8
Logic execution with the LOAD NOT command
Operands: M, I, O, T, C
Operation:
The complement of the addressed operand is loaded into the Logic Accumulator. A load command is
always used at the start of a logic chain in order to enable subsequent gating commands. The same
function is achieved when the gating commands AN, ON, XON are used at the start of a logic chain,
however this should only be used when compatibility with TNC 355 is required.
Example:
The inverted logic state of Input I4 and Input I5 is to be gated with AND and the result assigned to
Output O2. Thus the inverted logic state of Input I4 is loaded into the Accumulator to enable
subsequent gating commands.
Initial state:
Input
I4 = 0
Input
I5 = 1
Output
O2 = ?
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
LN I4
... x x x x x x 1 x x x x x x x
0
2
A I5
... x x x x x x 1 x x x x x x x
1
3
= O2
... x x x x x x 1 x x x x x x x
1
Line 1:
The inverted operand contents are loaded into the Logic Accumulator.
Line 2:
The contents of the Logic Accumulator and Input I5 are gated with AND.
Line 3:
The gating result is assigned to Output O2.