1
10 Series 90 -70 I/O Link Interface Module User’s Manual – February 1993 GFK-0644A
Data Sent by the Master
The master sends output data for all slave devices together. If a Series 90–70 PLC is the
master on an I/O Link, it simply places the data to be sent into the %Q output references
assigned to the I/O Link Interface Module.
Slaves receive the data in order of their positions on the link. Each slave in turn reads
out its configured amount of data, and passes the remainder on to the next slave. To a
slave, data received from the master is input data. If a Series 90–70 PLC is a slave, it
obtains the data received from the master by reading the %I input references assigned to
the I/O Link Interface Module.
a45009
MASTER SLAVE
1
INPUTS
OUTPUTS 1
OUTPUTS
OUTPUTS
OUTPUTS
OUTPUTS
OUTPUTS
2
3
2
3
3
SLAVE
2
INPUTS
SLAVE
3
INPUTS
Data Returned by Slaves
The master continuously reads the output data from each slave. If a Series 90–70 PLC is
a slave, it provides this data by placing it into the %Q references configured for the I/O
Link Interface Module. If a Series 90–70 PLC is the master, it reads the data from the %I
references assigned to the I/O Link Interface Module.
a45004
MASTER
INPUTS
SLAVE
1SLAVE
2SLAVE
3
MASTER SLAVE
1SLAVE
2SLAVE
3
OUTPUTS
The master identifies each set of data it receives with respect to the slave’s position on
the link. To the master, data received from slaves is input data.