Label Communication Function - Mitsubishi Electric MELSEC iQ-R C User Manual

Label communication function

Data can be read from/written to labels stored in a CPU module.
Label communication flow
CPU module
(Label definition side)
Label assignment information
Label name
Label1
Label2
Label3
1.
Acquire label assignment information (device information) of the specified label with the MELSEC iQ-R series data link
function (mdrGetLabelInfo).
2.
Read/write data from/to a device based on the acquired label assignment information (device information) by using each
MELSEC iQ-R series data link function (mdrRandRLabel/mdrRandWLabel).
• In the label communication, a CPU module can be accessed without changing a user program by acquiring
label assignment information again even if the label assignment information of the CPU module is changed.
• The label assignment information (device information) acquired by using the MELSEC iQ-R series data link
function (mdrGetLabelInfo) does not need to be acquired for each MELSEC iQ-R series data link function
(mdrRandRLabel/mdrRandWLabel) execution. However, if the label assignment information (device
information) stored in a CPU module is changed, acquire it again by using the MELSEC iQ-R series data
link function (mdrGetLabelInfo). (Otherwise, an error response is returned.)
■Function list
The following table shows the functions used for label communication.
Function name
mdrGetLabelInfo
mdrRandRLabel
mdrRandWLabel
1 FUNCTION
16
1.1 Program Related Function
Obtain an information of the corresponding
devices using specified label (Label1, Label2).
Assignment target
(Device name)
D0
D1
X0
Execute Reading/Writing for the device
Description
To acquire device information corresponding to label names.
To read devices corresponding to labels randomly.
To write devices corresponding to labels randomly.
corresponding to the label.
C intelligent function module
(reference side)
User program
1. Execute the mdrGetLabelInfo function.
2. Execute the
mdrRandRLabel/mdrRandWLabel function.