Copyright Goodheart-Willcox Co., Inc. Chapter 6 PLC Programming 105 +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 Stop Start Jog Motor Bell M Goodheart-Willcox Publisher Figure 6-27. Input/output connections for Figure 6-26. Goodheart-Willcox Publisher Table 6-5. Input/output address assignments for Figure 6-26. Input Ports Output Ports Stop = I:0/0 Motor = O:0/0 Start = I:0/1 Bell = O:0/1 Jog = I:0/2 Place the PLC in the offline mode and create the ladder logic diagram displayed in Figure 6-28. Offline mode is the mode in which the PLC ladder logic diagram is created. Next, place the PLC in the online mode. This is the mode in which the PLC program can be downloaded into the PC. Follow the instructions provided by the RSLogix 500 software to download the program into the PLC. (Note that the Upload command transfers the program from the PLC to the PC.) Finally, place the PLC in the run/online monitor mode. When the PLC is in the run/online monitor mode, the run mode icon on the top of the screen rotates along its vertical axis. Also, when the PLC is in the run/online monitor mode, the two vertical rails in the ladder logic diagram become highlighted. Press the start pushbutton to turn the motor on in continuous run mode. When the motor is energized, the contact for relay coil B3:0/0 will close. Therefore, the motor will run continuously until the stop pushbutton is pressed. Notice that when an instruction is energized, its symbol on the screen is highlighted. Press the jog pushbutton to turn the motor on temporarily. The motor will run only when the jog pushbutton is pressed.