Transmission Procedure - Mitsubishi Electric MELSEC iQ-R Series User Manual

Transmission procedure

The following describes the transmission procedure when a message containing user frames is transmitted to the target
device.
Procedure
Target device
CPU module(*1)
CPU module
Completion device
Status display device
at completion
*1 Designate the user frame number for the data to be sent.
*2 CPU module processing
Before issuing a transmission request to C24, designate (write) the following data.
 Send user frame designation area : User frame number, transmission method and transmission order registered in C24
 Send area (Buffer memory): User data corresponding to arbitrary data portion in the transmission message
*3 When a send data quantity designation error or data transmission error occurred, C24 stores the error code to the transmission result
storage area of control data for PRR instruction, and the status display device at completion turns ON.
15 DATA COMMUNICATIONS USING USER FRAMES
314
15.4 Data Transmission
User frame User frame
(1st) (nth)
(*2)
TO
(*3)
Arbitrary data User frame
(mth)
Transmission
area data
PRR
User frame
(±th)
ON
ON
Abnormal
completion
Normal
completion
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