Homework answers / question archive /   To make it a little easier to see what is happening with the counter, you might want to add the following rung to the end of your program

  To make it a little easier to see what is happening with the counter, you might want to add the following rung to the end of your program

Electrical Engineering

Share With

---

 

To make it a little easier to see what is happening with the counter, you might want to add the following rung to the end of your program.

Basic Programmable Logic Controllers

 

 

  

 

 

Lab 9            Batch mixing operation

From the Simulations Menu at the top of the screen, select the Batch Mixing Simulation.

Using your knowledge of PLC timers and counters, design a program to meet the following requirements:

• When the Start button (I:1/0) is pressed, PUMP 1 will be energized and the tank will start to fill. The pulses generated by FLOWMETER 1 at input I:1/05 should be used to increment a counter C5:1. The RUN light (O:2/05) should be on while the tank is filling.
• When the count reaches a value where the tank is approximately 90% full, the pump should be automatically stopped and the control panel FULL light (O:2/07) is to be energized. You will need to experiment, to find the counter preset value which corresponds to about 90% full. 
• The mixer O:2/00 should now start, and run for 10 seconds.
• When the 10 seconds mix time is done, PUMP 3 O:2/03 should start, and the mixer will begin to empty. At this time, the FULL light should go off.
• When the mixer is empty, as shown by the LO-LEVEL I:1/3, the fill cycle should automatically restart. At this time, the counter should be reset using a RES instruction.
• The filling operation is to stop immediately if the stop switch is pressed.
• While testing, utilize the "Reset Simulation" and the "Reset Timers and Counters" entries in the Simulations menu if you need to restart your program.

Remember, it is very important to thoroughly test your program by “Downloading to PLC”, “Go Online” and “Run”.

The program should follow the above sequence of operations EXACTLY.

 

 

If correctly entered, the TOD (To BCD) instruction will take the integer value in the counters accumulator, convert it to Binary Coded Decimal, and then move (copy) this BCD value to the control panel LED display (O:4). The TOD instruction can be located in the Compute/Math group of instructions in the Edit Panel.