Copyright Goodheart-Willcox Co., Inc. Chapter 6 PLC Programming 95 When creating a new PLC file, the first step is to select the proper PLC processor. Figure 6-11 displays the Select Processor Type dialog box in the Rockwell RSLogix 500 e software. For an Allen-Bradley fixed PLC with twelve 120 VAC inputs and eight 120 VAC outputs, the processor type is 1747-L20A, as highlighted in the figure. Figure 6-12 shows the PLC ladder diagram for the relay logic diagram displayed in Figure 6-9. Motor #1 +120 V I0 I1 I2 I3 I4 I5 I6 I7 I8 I9 I10 I11 Input ports Common O0 O1 O2 O3 O4 O5 O6 O7 Output ports Pushbutton Switch Limit switch R Goodheart-Willcox Publisher Figure 6-10. Input/output connections for Figure 6-9. Goodheart-Willcox Publisher Figure 6-11. Select the fixed PLC type 1747-L20A for the Allen-Bradley fixed PLC with twelve 120 VAC inputs and eight 120 VAC outputs.