Functions; Functions For Exchanging With Slaves - Mitsubishi Electric MELSEC QJ71PB92D User Manual

4 FUNCTIONS

4. FUNCTIONS

4.1 Functions for Exchanging with Slaves

4
Input image
Output image
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The main function in the QJ71PB92D is for exchanging I/O data with slave stations
connected to the PROFIBUS-DP network. The method used for this exchange is to
read/write the I/O image in the buffer memory using auto refresh setting, FROM/TO
instruction, or dedicated instruction.
A schematic drawing of this exchange function is as follows.
CPU module QJ71PB92D
Buffer memory
Read
1
Write Output
image
2
Input image
Output image
(Class 1 master)
Input
image
Slave station
MELSEC-Q
Input
image
1: Either auto refresh, FROM
instruction, or dedicated
instruction (BBLKRD)
Output
2: Either auto refresh, TO
image
instruction, or dedicated
instruction (BBLKWR)
PROFIBUS-DP network
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