Specifications

64I/O Mapping

I/O Mapping

The purpose of I/O mapping is an easier access to the input and output data cyclically exchanged

between the Profibus master and the connected slaves. In I/O mapping GXDP generates PLC

program code, which will

transfer output data from buffer devices to the buffer memory of the master

transfer input data from the buffer memory of the master to the buffer devices

generate ‘Data Unit Types’ (DUTs) for each slave module

exchange data with devices selected by the user

start the cyclic data exchange

copy contents of diagnostic buffers to assigned devices

reference I/O data via global variables

Instead of calculating the I/O data offsets of the slave modules within the I/O buffer of the master,

one can read or write the respective global variables for slave modules. These are part of the user

library, which is generated via the menu item

POU for GX IEC Developer

I/O mapping program code is only available for the following master modules and operating

modes

A(1S)J71PB92D (Mode E only !)

QJ71PB92D (Mode E only!)

QJ71PB92V

FX3U-64DP-M

For the FX3U-64DP-M master module there is also a ‘Copy POU’ available, alternatively to the

'I/O Mapping POU'. It contains the code for exchanging I/O data between the buffer memory of the

master and the slave specific device areas in the CPU and can handle data consistency. The

'Copy POU' does not however include any information on the I/O structure of the slaves.

Note:

There is no I/O mapping and/or Copy POU support for A(1S)J71PB92D and

QJ71PB92D in mode 0.

Dialog for I/O Mapping

To access the dialog for I/O Mapping select a slave in the in the graphical network editor and then

select the item ‘I/O Mapping’ from the context menu.

The dialog is split into two panes

the left pane with a tree of the master, slaves and slave modules

the right pane with the I/O areas of the selected slave or module

Tree View