Omron SYSDRIVE 3G3RV Series User Manual page 313

nProtocol Macro Function
The protocol macro function makes it possible to customize a communications protocol in order to create a
macro according to the specifications of the serial communications port of a general-purpose peripheral
device.
The protocol macro function is mainly used for the following jobs.
• Creation of the message communications frame
Creation of Send & Recv procedures for the message communications frame
•
This manual uses the terms "message, DSR message, and response" to express the communications data
exchanged.
Message: A DSR message or response.
TERMS
DSR message: A message sent by the Master for instructions to the Inverter.
Response: A message that the Inverter returns in compliance with a DSR message from the Master.
Creating a Message
The message can be created according to the communications specifications of the general-purpose peripheral
device (Inverter) as a counterpart.
A DSR message can include variables to set data in the I/O memory (such as data memory) of the CPU Unit or
write response data to the I/O memory.
Each component of a message is in the memory of the Communications Board. Therefore, the CPU Unit can
just execute the PMCR instruction to send or receive the data, with no need to write ladder programs for the
communications protocol.
Serial Communications Board
CPU Unit
PMCR Instruction
Step to Send and Receive Messages
Sending and receiving messages as a single step includes step-type commands, such as Send, Recv, Send &
Recv, and Wait commands.
The step can be finished or switched to another step according to the result of the step.
Serial Communications Board
CPU Unit
PMCR Instruction
Next process
according to
Reception
Fig 6.62 Creating a Message
the result.
Fig 6.63 Sending and Receiving Messages
Communications Functions
SYSDRIVE 3G3RV
DSR message
Send
Response
SYSDRIVE 3G3RV
Step 0
To step n according
to the result
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