Ladder Program - Omron CJ Series Connection Manual

9.5. Ladder program

9.5.1. Functional Components of the Ladder Program
The functional components of this program are shown below.
Major classification
1.Initialization 1.1. Response code clear
processing 1.2. Control word setting for
1.3. Send/Receive symbol
2.CMND instruction 2.1. CMND instruction
execution
management 2.2. CMND instruction
2.3. Normal/Error detection
3.Normal end state 3.1. Normal end processing
management 3.2. Response code setting
4.Error end state 4.1. Error end processing
management 4.2. Response code setting
9.5.2. Detailed Description of Each Functional Component
The program configured in this document is shown below.
●1. Initialization processing
No. Outline
1.1. Response code
clear
Minor classification
CMND instruction
setting
executing
execution processing
processing.
The Error code storage area is initialized.
Description
The area of use is cleared and the
initialization setting is performed as a
preparation for communications.
CMND instruction (Modbus-RTU
communication) is executed. A normal end
or an error end is detected based on the
related flags and receive data.
The normal completion flag is turned ON.
The response code for a normal end is set.
The error end flag is turned ON.
The response code corresponding to an
error cause is set.
Description
9．Program
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