Omron SYSMAC CVM1 Series Operation Manual page 94

Mnemonic Code
Complicated Diagrams
Block
a1
0000 0000 0000
00 01 04
0000 0000 0000
02 03 06
Block
a2
Block
a
76
When determining what logic block instructions will be required to code a dia-
gram, it is sometimes necessary to break the diagram into large blocks and then
continue breaking the large blocks down until logic blocks that can be coded
without logic block instructions have been formed. These blocks are then coded,
combining the small blocks first, and then combining the larger blocks. Either
AND LOAD or OR LOAD is used to combine the blocks, i.e., AND LOAD or OR
LOAD always combines the last two execution conditions that existed, regard-
less of whether the execution conditions resulted from a single condition, from
logic blocks, or from previous logic block instructions.
When working with complicated diagrams, blocks will ultimately be coded start-
ing at the top left and moving down before moving across. This will generally
mean that, when there might be a choice, OR LOAD will be coded before AND
LOAD.
The following diagram must be broken down into two blocks and each of these
then broken into two blocks before it can be coded. As shown below, blocks a
and b require an AND LOAD. Before AND LOAD can be used, however, OR
LOAD must be used to combine the top and bottom blocks on both sides, i.e., to
combine a1 and a2; b1 and b2.
Block
b1
0000
05
0002
07
Block
b2
Block
b
The following type of diagram can be coded easily if each block is coded in order:
first top to bottom and then left to right. In the following diagram, blocks a and b
would be combined using AND LOAD as shown above, and then block c would
be coded and a second AND LOAD would be used to combined it with the execu-
tion condition from the first AND LOAD. Then block d would be coded, a third
AND LOAD would be used to combine the execution condition from block d with
the execution condition from the second AND LOAD, and so on through to
block n.
Block Block
a
Address Instruction Operands
0005
00000
03
00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
Block
b c
Section 4-4
LD 000000
AND NOT 000001
LD NOT 000002
AND 000003
OR LD —
Blocks a1 and a2
LD 000004
AND 000005
LD 000006
AND 000007
OR LD —
Blocks b1 and b2
AND LD —
Blocks a and b
OUT 000503
0005
00
Block
n