Omron CJ1G-CPUxx, Instructions Manual

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General Instruction Characteristics Section 1-1
• CJ1 CPU Units
• CJ1M CPU Units
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 7 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.
1-1-2 Differentiated Instructions
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.
• An upwardly differentiated instruction is executed only once after its exe-
cution condition goes from OFF to ON.
CJ1G-CPU43H 20K steps 960
CJ1G-CPU42H 10K steps
Model Program capacity I/O points
CJ1G-CPU45 60K steps 1,280
CJ1G-CPU44 30K steps
Model Program capacity I/O points
CJ1M-CPU23 20K steps 640
CJ1M-CPU22 10K steps 320
CJ1M-CPU13 20K steps 640
CJ1M-CPU12 10K steps 320
Model Program capacity I/O points