Programmable Logic Control

Programmable Logic Control

• Submitted By: yycyap
• Date Submitted: 11/16/2009 9:03 AM
• Category: Technology
• Words: 740
• Page: 3
• Views: 650

Objectives:
1. To understand how to use the logic functions in PneuAlpha Software.
2. To simulate the scenario given below and write the program to PLC device.
3. To manipulate the PLC device as the controller to control the real mobile robot.
4. To understand interaction between PLC device and the other hardware components.

Scenario:
As a finalist for the Robocon, we are requires to program a mobile robot to move forward, backward, turn left and turn right at any time, using push buttons. The various movements of the mobile robot are performed by the combination of the rotation direction of two wheels. The mobile robot is actuated by two DC motors which can be distinguished by a left-hand side and a right-hand side in the back view of the mobile robot. A PCB board (motor drive) of DC motor driver is inlaid to equip the motors with the functionality of rotation in either clockwise or counter-clockwise directions. This means there are two channels (clockwise channel and counter-clockwise) as control input for each motor. If the signal in clockwise channel is “1”, the motor runs clockwise direction. Whereas, when the signal in counter-clockwise is “1”, the motor runs counter-clockwise. In our case, the PLC device is used to produce those CW/CCW signals to control the rotation of DC motors. TO control the rotation directions of the left-hand side motor, we employ 2 signals (CW/CCW) output by PLC device. In the same way, another 2 signals are used to control the right-hand side motor.

Programming and Performing:

Input: 1 Forward button (FW)
1 Backward button (BW)
1 Turn Left button (TL)
1 Turn Right button (TR)

Outputs: Ch1 = Left motor rotation CCW: 1 = Yes / 0 = No
Ch2 = Left motor rotation CW: 1 = Yes / 0 = No
Ch3 = Right motor rotation CW: 1 = Yes / 0 = No
Ch4 = Right motor rotation CCW: 1 = Yes / 0 = No
Solutions:

Logic Table:
|Input...