1-1-11 Program Capacity; 1-1-12 Basic Ladder Programming Concepts - Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual

Programming Concepts
DLNK(226)
(CP1H CPU Units)

1-1-11 Program Capacity

1-1-12 Basic Ladder Programming Concepts

General Structure of the
Ladder Diagram
22
The CPU BUS UNIT I/O REFRESH instruction (DLNK(226)) can be used to
refresh memory allocated to CJ-series CPU Bus Units in the CIO and DM
Areas, as well as data link data and other data specific to the CPU Bus Units.
The unit number of the CPU Bus Unit is specified when DLNK(226) is exe-
cuted to refresh all of the following data at the same time.
• Words allocated to the Unit in CIO Area
• Words allocated to the Unit in DM Area
• Special refreshing for the Unit (e.g., data links for Controller Link Units or
remote I/O for DeviceNet Units)
The maximum program capacities of the CP-series CPU Units for all user pro-
grams (i.e., the total capacity of all tasks) are given in the following table. All
capacities are given as the maximum number of steps. The capacities must
not be exceeded, and writing the program will be disabled if an attempt is
made to exceed the capacity.
Each instruction is from 1 to 7 steps long. Refer to SECTION 4 Instruction
Execution Times and Number of Steps for the specific number of steps in
each instruction. (The length of each instruction will increase by 1 step if a
double-length operand is used.)
Series
CP Series CP1H
CPU Units
CP Series CP1L
CPU Units
Note Memory capacity for CP-series PLCs is measured in steps, whereas memory
capacity for previous OMRON PLCs, such as the C200HX/HG/HE and CV-
series PLCs, was measured in words. Refer to the information at the end of
SECTION 4 Instruction Execution Times and Number of Steps for guidelines
on converting program capacities from previous OMRON PLCs.
Instructions are executed in the order listed in memory (mnemonic order). The
basic programming concepts as well as the execution order must be correct.
A ladder diagram consists of left and right bus bars, connecting lines, input
bits, output bits, and special instructions. A program consists of one or more
program runs. A program rung is a unit that can be partitioned when the bus is
split horizontally. In mnemonic form, a rung is all instructions from a LD/LD
NOT instruction to the output instruction just before the next LD/LD NOT
instructions. A program rung consists of instruction blocks that begin with an
LD/LD NOT instruction indicating a logical start.
CPU Unit type Model
XA CP1H-XA40D@-@
X CP1H-X40D@-@
Y CP1H-Y20DT-D
M CP1L-M40D@-@
CP1L-M30D@-@
L CP1L-L20D@-@
CP1L-L14D@-@
Section 1-1
Max. program capacity
20K steps
10K steps
5K steps