1678 HEIDENHAIN Technical Manual MANUALplus 620
8.15.18 AND (A)
Logic processing
with the AND
command
Syntax: A (AND)
Operands: M, I, O, T, C
Action:
At the beginning of a logic sequence, this command functions like an L
command, i.e., the logical state of the operand is loaded into the logic
accumulator. This is to ensure compatibility with the TNC 355, which does
not have the special L command. In PLC programs, a sequence of logical
gating operations should always be started with a load command (see L, LN,
L–).
Within a logic sequence, gate the content of the logic accumulator and the
logical state of the operand with AND. The control saves the result of the
operation in the logic accumulator.
Example:
Gate the inputs I4 and I5 with AND, and assign the result to output O2.
Initial state:
Input I4 = 1
Input I5 = 0
Output O2 = ?
Function STL Accumulat
or content
Operand content
Load the operand content into
the logic accumulator.
L I4 1 1
Gate the content of the logic
accumulator and input I5 with
AND.
A I5 0 1
Assign the gating result to
output O2.
= O2 0 0