Chapter 4 Data Communication Using Bidirectional Protocol - Mitsubishi Electric MELSEC iQ-R Series User Manual

4
DATA COMMUNICATION USING
BIDIRECTIONAL PROTOCOL
This communication enables data transfer between a target device and a CPU module using the data format and transmission
control procedure for the bidirectional protocol.
The feature of this data communication is that a response message is sent from the data receiving side to the data sending
side to inform whether the communication has been completed.
Use this to check if the data communication has been completed normally.
Programs for transmitting and receiving data are required on the CPU module side.
When receiving data
Communication using the bidirectional protocol can be replaced with those of the predefined protocol.
The Predefined protocol support function of Engineering tool allows the easy replacement.
With the predefined protocol, the required program is only for starting communication according to the
specified protocol, and this can reduce the number of steps considerably.
For the communication using the predefined protocol, refer to the following chapter.
Page 26 DATA COMMUNICATION USING PREDEFINED PROTOCOL
Parameter setting for data communication using bidirectional protocol
Set the transmission specification, the communication protocol with target devices, and others.
Set "Bidirectional protocol" for "Communication protocol setting".
Navigation window  [Parameter]  [Module Information]  "Module Name"  [Module Parameter]  "Basic Settings"
 "Various control specification"
Configure other settings according to the system being used.
For details of the settings, refer to the following section.
Page 422 PARAMETER SETTING
4 DATA COMMUNICATION USING BIDIRECTIONAL PROTOCOL
86
Ò arget device sends data to the C24
Data
Arbitrary data
ENQ
length
When normal
When abnormal
Error
code
Ó
The C24 notifies whether the data
communication has been completed
normally by a response message.
Sum
check
code
ACK
NAK