1 Week 5 SEQUENTIAL MOTION (LDR) Matakuliah: Mechatronics 2 Tahun: 2005 Versi: 1.0/0

2 Learning Outcomes By the end of this session, students can develop Ladder Diagram to perform sequential motions.

3 Sequential Motion Sequential motion is meant to be performing 1 motion after the others. Performing sequential tasks in a parallel like fashion. The use of flags will overcome this problem. Latching concept. Controller and actuator concept. Latching concept in performing a sequential motion.

4 Flags & Latching Concept Flag is an internal relay and is most often used to memorize events. It must be declared in an allocation list prior to using it. Flags can be used in both conditional part and executive part. Latching concept allows to create a single solenoid valve to act as a double solenoid valve.

5 Implementation of Latching Concept ( L 1 ) F 0,0 ( F 0,0 ) F 0,0 S1S1

6 Implementation of Latching Concept (continued) F 0,0 = internal relay utility If S 1 switch (normally open) is pressed, then electric current will flow through F 0,0 coil and F 0,0 switch will be closed accordingly. A latch condition will occur.

7 A latch condition can be stopped by adding a normally closed switch into the system. This switch is required to cut the current which is flowing through F 0,0 coil. As no more current flow through F 0,0 coil, the F 0,0 switch will open and stop the latching condition.

8 Stopping the Latched Condition ( L 1 ) F 0,0 ( F 0,0 ) F 0,0 S1S1 S 2 (NC) NC = normally closed