7.2.2.1 Reading the Sensor Value
The ladder logic program shown in Figure 54, Figure 55 and Figure 56 continuously
reads the Sensor Value from register N20:01 in the Ethernet product at IP address
192.168.10.201 using a Message (MSG) instruction and stores it in F8:0 in the PLC.
Note that, on rung 3, the two words that make up the floating-point Sensor Value are
swapped before they're copied to the F8 file. The program is event-driven in that the
completion of a MSG instruction triggers the transmission of another one. A count of the
messages sent is kept as well as a count of any errors that may have occurred.
Figure 54: Part 1 of 3 of a ladder logic program that reads the Sensor Value from N20:01.
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Thermo Scientific AquaSensors
DataStick
Ethernet Communications User Guide
60