Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 43

General Instruction Characteristics
1-1-2 Differentiated Instructions
• CJ1-H CPU Units
Model
CJ1H-CPU67H-R
CJ1H-CPU66H-R
CJ1H-CPU65H-R
CJ1H-CPU64H-R
CJ1H-CPU67H
CJ1H-CPU66H
CJ1H-CPU65H
CJ1G-CPU45H
CJ1G-CPU44H
CJ1G-CPU43H
CJ1G-CPU42H
• CJ1 CPU Units
Model
CJ1G-CPU45
CJ1G-CPU44
• CJ1M CPU Units
Model
CJ1M-CPU23
CJ1M-CPU22
CJ1M-CPU21
CJ1M-CPU13
CJ1M-CPU12
CJ1M-CPU11
Note Program capacity for CS/CJ-series PLCs is measured in steps, whereas pro-
gram capacity for previous OMRON PLCs, such as the C-series and CV-
series PLCs, was measured in words. Basically speaking, 1 step is equivalent
to 1 word. The amount of memory required for each instruction, however, is
different for some of the CS/CJ-series instructions, and inaccuracies will occur
if the capacity of a user program for another PLC is converted for a CS/CJ-
series PLC based on the assumption that 1 word is 1 step. Refer to the infor-
mation at the end of SECTION 4 Instruction Execution Times and Number of
Steps for guidelines on converting program capacities from previous OMRON
PLCs.
The number of steps in a program is not the same as the number of instruc-
tions. For example, LD and OUT require 1 step each, but MOV(021) requires
3 steps. Other instructions require up to 15 steps each. The number of steps
required by an instruction is also increased by one step for each double-
length operand used in it. For example, MOVL(498) normally requires 3 steps,
but 4 steps will be required if a constant is specified for the source word oper-
and, S. Refer to SECTION 4 Instruction Execution Times and Number of
Steps for the number of steps required for each instruction.
Most instructions in CS/CJ-series PLCs are provided with both non-differenti-
ated and upwardly differentiated variations, and some are also provided with a
downwardly differentiated variation.
• A non-differentiated instruction is executed every time it is scanned.
Program capacity
250K steps
120K steps
60K steps
30K steps
250K steps
120K steps
60K steps
60K steps
30K steps
20K steps
10K steps
Program capacity
60K steps
30K steps
Program capacity
20K steps
10K steps
5K steps
20K steps
10K steps
5K steps
Section 1-1
I/O points
2,560
1,280
960
I/O points
1,280
I/O points
640
320
160
640
320
160
3