4
FUNCTIONS
4.1 Cyclic Transmission Function
4.1.2 1 : 1 communication (X/Y communication)
4 - 5
1
OVERVIEW
2
SYSTEM
CONFIGURATION
3
SPECIFICATIONS
4
FUNCTIONS
5
PREPARATORY
PROCEDURES BEFORE
OPERATION
6
LINK DATA SEND/
RECEIVE PROCESSING
AND PROCESSING TIME
7
PROGRAMMING
8
TROUBLESHOOTING
4.1.2 1 : 1 communication (X/Y communication)
Using a part of the I/O points assigned to a master station and a local station, one-to-one
data communication is performed between the master and local stations.
The sending and receiving sides are regarded as output (Y) and input (X) respectively.
(1) I/O ranges in X/Y
The I/O ranges of X/Y are set up with link parameters of the master station.
(2) Link refresh of link data
Q series local stations refresh link data using the sequence program. Note that
refresh is not executed when the CPU module is in STOP status.
CHAPTER 7 PROGRAMMING
(3) X/Y communication example
The following illustrates an example where input (X) and output (Y) data are
transferred between the master station and a Q series local station.
Figure 4.7 X/Y communication data flow
Figure 4.8 X/Y communication example
X
Y
X
Y
Y
X
Y
X
Data memory
storage area
Q series local station
Local module
CPU module
Master station
Link data
storage area
Link data
storage area
Buffer memory
Data memory
storage area
Link scan
Link refresh
Data flow (Send/receive processing)
Actual I/O
CPU module
Link
module
0
47F
400
Y400
Output
instruction
CPU module
Local module
buffer memory
Y480
Output
instruction
X480
Link refresh
Cyclic transmission
XY XY
0
400
Actual I/O
XY
47F197
H
190H
480
4FF
218H
21FH
X400
480
4FF
Program for refresh
Program for data link
END processing
Program for data link
END processing
Master station Q series local station
