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Name: _______________________
Name: _______________________
ME430 Mechatronic Systems: Control Problem for implementation on Pico PLC.
______________ Lab team has completed the tank mixer PLC project
______________ Lab team has completed the conveyor belt PLC project
40 inch
6 inch
11 inch
v ≈ 6 in/s
Break beam sensor 2: 1” above belt
Break beam sensor 1: 4” above belt
Can indexing unit Can indexing unit Chute deflection arm
Momentary NO switch
Motor
Full Tank Sensor Switch
Empty Tank Sensor Switch
Start/Stop Control Box
Solenoid B
Solenoid A
Tank mixer:
Create a ladder logic circuit to implement a PLC program to control the sequence of operations below. Run the simulation using PicoSoft. : a) Normally open start and stop pushbuttons are used to start and stop the process b) When the start button is pressed, solenoid A energizes to start filling the tank. c) As the tank fills, the empty level sensor switch (normally open) closes d) When the tank is full, the full level sensor switch (normally closed) opens. e) When the tank is full, Solenoid A is de-energized. f) The agitate motor starts automatically and runs for 10 seconds to mix the liquid g) When the mixing is done, solenoid B is energized to empty the tank. h) When the tank is empty, the empty sensor switch opens to de-energize solenoid B. i) The start button is pressed to repeat the sequence j) The stop button may be pressed at anytime to halt the process.
Test your system by simulating the control structure with your PicoSoft simulation software. When the simulation works perfectly show the instructor. After the instructor has seen your simulation connect to the tank mixer.
Motor
Full Tank Sensor Switch
Empty Tank Sensor Switch
Start/Stop Control Box
Solenoid B
Solenoid A
Conveyor Belt Project:
You are to create PLC process control program using PicoSoft to control the conveyor belt with indexing supply and chute sorting.
Output controls: System power (powering the belt and other devices) Indexing unit motor Chute deflection arm solenoid
Inputs or sensors you can monitor: Momentary switch Break beam sensor 2 (set to detect object 1”high) Break beam sensor 1 (set to detect object 4” high)
System Requirements: Pushing the momentary switch should toggle the system power off and on. (hint: check out how the a M output works as an Impulse Relay)
Detection of an object by Break Beam Sensor 2 should be used to turn on the index motor so another object is placed on the conveyor. This will need to include a sort timer to allow the indexing unit to engage (i.e a time delay of 0.5 seconds or so)
Detection of an object by Break Beam Sensor 1 indicates a tall can has passed and should be diverted to the tall chute. It should activate the deflection arm solenoid and hold it open until the can has left the conveyor. It should also increment a counter.
After 4 tall cans have been detected, the PLC is to turn the system power “off”. The system can be started again by pushing the momentary switch.
Create a PicoSoft control program that you can demonstrate.
40 inch
6 inch
11 inch
v ≈ 6 in/s
Break beam sensor 2: 1” above belt
Break beam sensor 1: 4” above belt
Can indexing unit Can indexing unit Chute deflection arm
Momentary NO switch
Test your system by simulating the new control structure with your PicoSoft
simulation software. When the simulation works perfectly show the instructor.
After the instructor has seen your simulation, connect to the conveyor belt.
On the conveyor belt run it without cans first to make sure your time
delays are appropriate. Adjust them as needed. Don’t add cans until
you expect them to work.
Conveyor connections:
The demo has the following inputs: I1: Break Beam Sensor 1 I2: Break Beam Sensor 2 I3: NO momentary switch
The demo uses the following outputs: Q1: Sort Arm Solenoid Q2: Index Motor Q3: System Power
When running the index motor, you will need to turn on the motor for about ½ second before the automatic motor latch kicks in. So consider using a timer on the index motor.
Check your program to make sure the input and output ports are in agreement with these devices.
If you have made any corrections to your program, run it through the simulator to verify that it works correctly.
If it seems to perform correctly, take your computer up to the demonstration station and download your program to the PLC.
L1 (L2) I1 I2 I3 I4 I5 I6 I7 I
Q1 Q2 Q3 Q
Esc Ok
Allen-Bradley Del Alt
Pico 1760-L12AWA-NC Output 4xRelay/8A
120/240V ac 50/60Hz Input 8 x 120/240V ac
NO Mom. Sw.
Sensor 2 switch
Sensor 1
Line
Neutral
Sort Index
Power
Step 2: Continuation of the PicoSoft Tutorial
Establishing a Connection with the Controller
Now that we have tested the circuit diagram, let's download it to the device.
Choose Communication , Interface , select the interface required (COM 1 ... 6 to match the COM identified in Step 1), and then click the Communication tab to move to the Communication View.
Choose Communication , Online to start another attempt to establish a connection with the device.
This PicoSoft/PicoSoft Pro view is also divided into three sections. It looks very much like the Simulation View and contains the Toolbox [1], a Properties field [2] and a Circuit Diagram [3] like the last two views described. The figure “Communication View” shows this view with its three divisions.
Downloading your program:
The Toolbox [1] will help us to do this. Proceed as follows:
- Click the Program button in the Toolbox. This will open the dialog for downloading and uploading the circuit diagram.
- Click on the Stop button if the PLC is running
- Click the Download button PC->Device. o The circuit diagram will be transferred if the device is in Stop mode. If this is not the case, a dialog will appear via which you can stop the device and proceed with the download process. The Properties field window [2] shows the progress bar via which you can see the current status of the data transfer.
Once the download has finished, we can then display the current status of the circuit diagram, the so-called “Power flow”, in the device:
- Start the device by clicking the RUN button in the Program dialog of the Toolbox [1]. Alternatively, you can choose Communication , Device RUN.
- Click the Play button. The power flow will start and the current states in the device will be displayed.
- Click the Stop button to stop the display of the Power flow.
Step 3: Run the demo
Press the red play button on the tank to start it
On the conveyor belt, push the black button and place a can on the
conveyor belt. On the conveyor belt run it without cans first to make
sure your time delays are appropriate. Adjust them as needed. Don’t
add cans until you expect them to work.
