Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 175)

Publication AG-UM008C-EN-P - February 2005
Configuring SLC 5/03, 5/04, and 5/05 Processors 4-37
Messaging Messaging can occur between:
•
a master station and a slave station
•
a slave station and its master station (See Polled
Report-by-Exception)
•
slave stations or between two processors connected via a radio
modem point-multipoint or full-duplex point-to-point link
Master Station to Slave Station
An SLC 5/03, 5/04, or 5/05 master station communicates with the slave
stations that are connected to it via modems in a point-to-multipoint
configuration. A master station sends a slave station message to
receive status or issue commands. For sample messaging ladder logic
to use as a guide when using Standard or Message-based Polling
Modes, see page E-2.
Polled Report-by-Exception
Slave stations can gather information from the I/O points they are
responsible for and can send any anomalous readings to the master
station. To do this, write ladder logic in the slave station to monitor
certain conditions and send the data in an MSG instruction to the
master station. For sample messaging ladder logic to use as a guide
when using an SLC 500 as a slave, see page E-6.