User Manual

Chapter 4
4–1
Module Programming
In this chapter you will learn about:
Reading data from the 1771–QRD module
Writing data to the 1771–QRD module
Black transfer programming format
Programming techniques
Block Transfer Read programming moves 9 words from the 1771–QRD
Module to the processor’s data table. The ladder program initiates the
request to transfer data from the QRD to the processor.
Figure 4.1 illustrates the module’s response after the PLC processor’s
block transfer request for counts and rates.
Figure 4.1
Module' s Response to Block T ransfer Read Request
Word 0 1 0 0 0
Word 1 Channel 1 Rate
Word 2 Channel 1 Total
Word 3 Channel 2 Rate
Word 4 Channel 2 Total
Word 5 Channel 3 Rate
Word 6 Channel 3 Total
Word 7 Channel 4 Rate
Word 8 Channel 4 Total
Chapter Objectives
Reading Data From The
Module