A PLC will be used with channels assigned as given in Section 5.4. Prepare a programmed ladder diagram for the system of given Figure as described in given Problem. All switches are NO. Thus, TH closes when the temperature reaches TH, L1 closes when the level exceeds L1, and so forth.
Problem
Figure shows a system for batch processing. The system operations can be described as follows:
(1) A weighed quantity of dry material is added to liquid that has filled the tank to level L1.
(2) The mixture is stirred, and heat is applied to maintain the temperature between TL and TH for a period of 10 minutes.
(3) With the stir and heater off, the batch is emptied down to level L2. The whole process then starts again. Prepare a flowchart that describes the sequence of events. Be sure to consider any events that could occur in parallel.
