Omron SYSMAC CV Series - Programming Precautions

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4-10 Programming Precautions

The number of conditions that can be used in series or parallel is unlimited as

long as the memory capacity of the PC is not exceeded. Therefore, use as many

conditions as required to draw clear diagrams. Although very complicated dia-

grams can be drawn with instruction lines, there must not be any conditions on

lines running vertically between two other instruction lines. Diagram A shown

below, for example, is not possible, and should be drawn as diagram B. Mne-

monic code is provided for diagram B only; coding diagram A would be impossi-

ble.

Diagram A

Diagram B

Address Instruction

00000 LD 000001

00001 AND 000004

00002 OR 000000

00003 AND 000002

00004 Instruction 1

00005 LD 000000

00006 AND 000004

00007 OR 000001

00008 AND NOT 000003

00009 Instruction 2

Operands

0000

Instruction 1

Instruction 2

Instruction 1

The number of times any particular bit can be assigned to conditions is not lim-

ited, so use them as many times as required to simplify your program. Often,

complicated programs are the result of attempts to reduce the number of times a

bit is used.

Except for instructions for which conditions are not allowed (e.g., INTERLOCK

CLEAR and JUMP END, see below), every instruction line must also have at

least one condition on it to determine the execution condition for the instruction

at the right. Again, diagram A , below, must be drawn as diagram B. If an instruc-

tion must be continuously executed (e.g., if an output must always be kept ON

while the program is being executed), the Always ON Flag (A50013) in the Auxil-

iary Area can be used.

Diagram A

Diagram B

Address Instruction

00000 LD A50013

00001 Instruction

Operands

Instruction

A500

Instruction

There are a few exceptions to this rule, including the INTERLOCK CLEAR,

JUMP END, and step instructions. Each of these instructions is used as the se-

cond of a pair of instructions and is controlled by the execution condition of the

first of the pair. Conditions should not be placed on the instruction lines leading to

these instructions. Refer to

Section 5 Instruction Set

for details.

Programming Precautions Section 4-10

Omron SYSMAC CV Series - Programming Precautions

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