223
Bit Control Instructions
Section 5-9
between the execution condition and the inverse of the status of its bit oper-
and. OR takes the logical OR between the execution condition and the status
of its bit operand; OR NOT, the logical OR between the execution condition
and the inverse of the status of its bit operand.
Flags
There are no flags affected by these instructions.
5-8-2
AND LOAD and OR LOAD
Description
When instructions are combined into blocks that cannot be logically combined
using only OR and AND operations, AND LD and OR LD are used. Whereas
AND and OR operations logically combine a bit status and an execution con-
dition, AND LD and OR LD logically combine two execution conditions, the
current one and the last unused one.
In order to draw ladder diagrams, it is not necessary to use AND LD and OR
LD instructions, nor are they necessary when inputting ladder diagrams
directly, as is possible from the CX-Programmer. They are required, however,
to convert the program to and input it in mnemonic form.
In order to reduce the number of programming instructions required, a basic
understanding of logic block instructions is required. For an introduction to
logic blocks, refer to
4-3-6 Logic Block Instructions
.
Flags
There are no flags affected by these instructions.
5-9
Bit Control Instructions
There are seven instructions that can be used generally to control individual
bit status. These are OUT, OUT NOT, DIFU(13), DIFD(14), SET, RSET, and
KEEP(11). These instructions are used to turn bits ON and OFF in different
ways.
Ladder Symbol
AND LOAD
−
AND LD
00002
00003
00000
00001
Ladder Symbol
OR LOAD
−
OR LD
00000
00001
00002
00003
