Electronics Systems Engineering Assignment-
1. Assuming the hardwired circuit (the term hardwired logic refers to logic control functions that are determined by the way devices are electrically interconnected. Hardwired logic can be implemented using relays and relay ladder schematics) drawn in Figure 1 is to be implemented using a PLC program, identify
a) All input field devices
b) All output field devices
c) All devices that could be programmed using internal relay instructions
d) Draw the corresponding Ladder Logic Diagram for the OMRON CP1L- M30DT PLC (the PLC that we have in our lab). You are required to use valid addresses.
|
PS
|
Pressure Switch
|
|
LS
|
Limit Switch
|
|
PB
|
Push Button
|
|
CR
|
Control Relay
|
|
SOL
|
Solenoid
|
|
PL
|
Pilot Light
|
|
|
|
2. Write the ladder logic program needed to implement each of the following (assume inputs A, B and C are normally open switches): [Note: Write separate program for each part]
a) When input A is closed, turn ON and hold ON outputs X and Y until A opens.
b) When input A is closed and either input B or C is open, turn ON output Y; otherwise, it should be OFF.
c) When input A is closed, turn ON output X and turn OFF output Y.
3. Figure 2 shows the sketch of a drilling process that requires the drill press to turn on only if there is a part present and the operator has one hand on each of the start switches. This precaution will ensure that the operator's hands are not in the way of the drill. The sequence of operation requires that switches 1 and 2 and the part sensor all be activated to make the drill motor operate. Draw the ladder logic program required for the process implemented using OMRON CP1L-M30DT PLC. You are also required to draw a wiring diagram for connecting the inputs and output to the PLC. Use valid addressing.
4. Figure 3 shows the sketch of a continuous filling operation. This process requires that boxes moving on a conveyor be automatically positioned and filled.
The sequence of operation for the continuous filling operation is as follows:
a) Start the conveyor when the start button is momentarily pressed.
b) Stop the conveyor when the stop button is momentarily pressed.
c) Energize the run status light when the process is operating.
d) Energize the standby status light when the process is stopped.
e) Stop the conveyor when the right edge of the box is first sensed by the photo-sensor.
f) With the box in position and the conveyor stopped, open the solenoid valve and allow the box to fill. Filling should stop when the level sensor goes true.
g) Energize the full light when the box is full. The full light should remain energized until the box is moved clear of the photo-sensor.