Omron G9SP-N20S Network Connection Manual page 30

9.1.1. Communications Data Flow
The following figure shows the data flow from when the Controller (SCU Unit) issues a
communications command (hereinafter referred to as command) to the destination device
until when the SCU receives the response data from the destination device.
1. Sending a command
2. Receiving a response
9.1.2. Serial Communications Instruction and Send/Receive Message
This section outlines the function blocks for Serial Communications Unit (hereinafter
referred to as serial communications instructions) and the general operation of the
send/receive messages.
Additional Information
For details, refer to Communications Instructions under Section 2 Instruction Descriptions of
NJ-series Instructions Reference Manual (Cat. No. W502).
●Serial communications instructions
In this project file, serial communications are performed by using the following 2 types of
standard instructions.
Name
SCU Send Serial
SCU Receive Serial
●Serial communications instructions argument data
·SCU Send Serial
The SCU Unit sends the send message set with the
ladder program to the destination device.
↓
The response data, which was received by the SCU
Unit from the destination device, is stored in the
specified internal variable of the CPU Unit.
Function blocks
SerialSend
SerialRcv
Description
Sends data in No-protocol Mode from a
serial port. (Send instruction)
Reads the receive data from the serial port in
No-protocol Mode. (Receive instruction)
9. Project File
27