Below is a general guide you can follow in Multisim to set up and simulate the logic circuit for the filling machine. This guide outlines the necessary steps and components based on the logic expressions we defined:
Overview of the Logic Functions
Valve (V):
The valve should be active when a bidón is in the filling position and not yet full, given by the equation
V=A⋅X
A: Sensor indicating a bidón in position under the filling nozzle.
X: Sensor that indicates the bidón is full. (Its inversion provides the signal for “not full”.)
Motor (M):
The motor should run only when the bidón is not in the critical filling or pause stages, as given by
M=P⋅B⋅(A+X)
P: Pedal de parada – when active (logic 1), stops the motor.
B: Sensor at the final position of the belt that stops the motor if a bidón reaches the end.
A: As above, sensor detecting the bidón under the nozzle.
X: As above, indicating the bidón is full.
Steps to Set Up the Circuit in Multisim
Start a New Project:
Open Multisim and create a new circuit schematic.
Place Logic Gate Components:
Inverters:
Use inverter gates to generate the complementary signals:
For X to get X.
For A to get A.
For P to get P.
For B to get B.
AND Gates:
One AND gate will combine A and X to generate the valve signal V.
For the motor, first combine P and B in an AND gate.
Then use another AND gate to combine the result from the previous stage with the output of an OR gate.
OR Gate:
Use an OR gate to combine A and X for the motor logic.
Assign and Label Inputs and Outputs:
Use digital input components or signal sources for the inputs A, X, B and P.
Use digital probes or indicator LEDs for outputs V and M so you can observe their states during simulation.
Connect the Components According to the Logic Diagram:
Valve Circuit:
Connect input A directly to one input of an AND gate.
Pass input X through an inverter to obtain X and feed this into the other input of the same AND gate.
Motor Circuit:
Invert P and B separately to obtain P and B.
Use an AND gate to combine these two inverted signals.
In parallel, invert A (to get A) and take X as is, then use an OR gate to combine these to form A+X.
Finally, connect the output of the AND gate (from P⋅B) and the output of the OR gate (from A+X) into a final AND gate. The output of this gate is the motor signal M.
Run the Simulation:
Toggle the inputs to mimic sensor activations (for example, setting A = 1 when a bidón is under the nozzle) and observe the outputs (LEDs or digital probes) for V and M.
Verify that when A = 1 and X = 0, the valve output V is active.
Also, test other combinations to ensure M follows the conditions defined by the motor logic.
Additional Tips
Label all wires and components clearly to avoid confusion during simulation.
Use the simulation tools in Multisim (such as oscilloscopes or logic analyzers) to monitor the logic levels.
Double-check each connection so that the proper gate inputs are connected according to the defined logical expressions.
This guide provides a framework for setting up the circuit. You may need to adapt it to the specific details of the Multisim version or library components available in your setup.
If you have any further questions or need clarification on a particular step in Multisim, let me know!
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
General Purpose Thick Film Standard Power
and High-Power Chip Resistor
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film
Features:
- RMCF – standard power ratings
- RMCP – high power ratings
- Nickel barrier terminations standard
- Power derating from 100% at 70ºC to zero at +155ºC
- RoHS compliant, REACH compliant, and halogen free
- AEC-Q200 compliant