Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 104)

Publication AG-UM008C-EN-P - February 2005
3-36 Configuring MicroLogix 1100/1200/1500 Controllers
DF1 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-to-multipoint or full-duplex point-to-point link
Master Station to Slave Station
A MicroLogix 1100/1200/1500 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 a MicroLogix 1100/1200/1500 as a Slave, see page E-6.
Duplicate Messages
Received CSx:18 The number of times the processor received a message packet identical
to the previous message packet
ENQs Sent CSx:13 The number of ENQs sent by the processor
Bad Packet/Sent NAK CSx:16 The number of incorrect data packets received by the processor for which
a NAK was returned
RTS (Request to Send) CSx:9/1 The status of the RTS handshaking line (asserted by the processor)
CTS (Clear to Send) CSx:9/0 The status of the CTS handshaking line (received by the processor)
DCD (Data Carrier Detect)
(1) CSx:9/3 The status of the DCD handshaking line (received by the processor)
(1) Only present on the MicroLogix 1500 LRP channel 1.
(2) The channel number equals x.
Table 3.10 Understanding The DF1 Full-Duplex Status Screen Fields
Status Field Communication Status
Function File Location
(2)
Definition