Schneider Electric: Car Parking System with Calculations in PLC

Learn to program a car parking system with Schneider Electric PLCs including detailed calculations and step-by-step instructions.

Contents

Car Parking System with Calculations

This article discusses car parking systems which are widely used in Malls, Offices, and other Public Places. This system has 1 GATE to Enter the parking area and 1 GATE to Exit the parking area.

Every car Entering and Exiting the parking area will be recorded on the system. When the car is detected then the GATE will Open (Up) and then it will Close (Down) after the car passes through the GATE.

PLC Logic Explanation

Schneider Electric Car Parking System with Calculations in PLC

PLC Based Automatic Intelligent Car Parking System

This PLC program has 3 buttons, The START_SYSTEM (I0.0) button is used to Activate the system, the STOP_SYSTEM (I0.1) button is used to Stop the system, and the RESET_COUNTER (I0.2) button is used to Reset the COUNTER (MW0) Memory data to the Zero value “0”.

“GATE IN” and “GATE OUT” have a similar system and each has 4 sensors. For example, in “GATE IN”, the SENS_CAR_IN1 (I0.3) sensor is used to detect a car that is about to Enter, the LS_GATE_IN_UP (I0.7) sensor is used as a limiter for the maximum number of cars through the GATE. The SENS_CAR_IN2 (I0.4) sensor is used to detect the car has passed through the exit GATE, The LS_GATE_IN_DOW (I0.8) sensor is used for the lowest point limiter for the GATE.

When the SENS_CAR_IN1 (I0.3) sensor is Active, it will Activate the GATE_IN_UP (Q0) output so that the GATE Opens. GATE will Stop Opening/Rising when Sensor LS_GATE_IN_UP (I0.7) is Active. After the car passes the GATE, the SENS_CAR_IN2 (I0.4) sensor will be Active for a moment and Activate the GATE_IN_DOWN (Q1) output. GATE Closes again and it will Stop the lowering command when Sensor LS_GATE_IN_DOWN (I0.8) is Active.

When the SENS_CAR_IN1 (I0.3) sensor is Active, the data in the Word COUNTER (D0) memory will increase (+1). When the SENS_CAR_OUT1 (I0.5) sensor is Active, the data in the Word COUNTER (D0) memory will decrease (-1).

Inputs and Outputs Details

Addressing Input, Output, TIM, Bit Memory, and Word Memory details are as follows.

Comment	Input (I)	Output(Q)	Word Memory	Memory Bits
START_SYSTEM	I0.0
STOP_SYSTEM	I0.1
RESET_COUNTER	I0.2
SENS_CAR_IN1	I0.3
SENS_CAR_IN2	I0.4
SENS_CAR_OUT1	I0.5
SENS_CAR_OUT2	I0.6
LS_GATE_IN_UP	I0.7
LS_GATE_IN_DOWN	I0.8
LS_GATE_OUT_UP	I0.9
LS_GATE_OUT_DOWN	I0.10
COUNTER			MW0
IR_SYSTEM				M0
IR_GATE_IN_UP				M1
IR_GATE_IN_DOWN				M2
IR_GATE_OUT_UP				M3
IR_GATE_OUT_DOWN				M4
GATE_IN_UP		Q0
GATE_IN_DOWN		Q1
GATE_OUT_UP		Q2
GATE_OUT_DOWN		Q3

PLC Programming

RUNG 0 (SYSTEM 0N)

When the START_SYSTEM (I0.0) button is pressed then the IR_SYSTEM (M0) Bit Memory Coil will be Active. Because it uses the Latching function, the IR_SYSTEM (M0) Bit Memory Coil will remain active even though the START_SYSTEM (I0.0) button is released.

Bit Memory Coil IR_SYSTEM (M0) will be OFF when STOP_SYSTEM (I0.1) contact is ON.

RUNG 1 (COUNTER AREA)

This Rung functions to Add, Subtract, and Reset COUNTER (D0) data. When the SENS_CAR_IN1 (I0.3) sensor is ON, the data on COUNTER (D0) will increase (+1).

When the SENS_CAR_OUT1 (I0.5) sensor is ON, the data on COUNTER (D0) will decrease (-1). When the RESET_COUNTER (I0.2) button is pressed, the data on COUNTER(D0) will be reset to Zero “0”.

RUNG 2 (GATE IN UP)

When the IR_SYSTEM (M0) contact and SENS_CAR_IN1 (I0.3) are ON, the IR_GATE_IN_UP (M1) Coil will be Active. Because the IR_GATE_IN_UP (M1) Coil uses the Latching function, the IR_GATE_IN_UP (M1) Coil will remain active even though the SENS_CAR_IN1(I0.3) sensor is OFF. When the LS_GATE_IN_UP (I0.7) contact is Active, the IR_GATE_IN_UP (M1) coil will be Disabled.

RUNG 3 (GATE IN DOWN)

When the IR_SYSTEM (M0) contact and SENS_CAR_IN2 (I0.4) are ON, the IR_GATE_IN_DOWN (M2) Coil will be Active. Because the IR_GATE_IN_DOWN (M2) Coil uses the Latching function, the IR_GATE_IN_DOWN (M2) Coil will remain active even though the SENS_CAR_IN2 (I0.4) sensor is OFF. When the LS_GATE_IN_DOWN (I0.8) contact is Active, the IR_GATE_IN_DOWN (M2) coil will be Disabled.

RUNG 4 (GATE OUT UP)

When the IR_SYSTEM (M0) contact and SENS_CAR_OUT1 (I0.5) are ON, the IR_GATE_OUT_UP (M3) Coil will be Active. Because the IR_GATE_OUT_UP (M3) Coil uses the Latching function, the IR_GATE_OUT_UP (M3) Coil will remain Active even though the SENS_CAR_OUT1 (I0.5) contact has been Disabled. When the LS_GATE_OUT_UP (I0.9) contact is Active, the IR_GATE_OUT_UP (M3) coil will be Disabled.

RUNG 5 (GATE OUT DOWN)

When the IR_SYSTEM (M0) contact and SENS_CAR_OUT2 (I0.6) sensors are ON, the IR_GATE_OUT_DOWN (M4) Coil will be Active. Because the IR_GATE_OUT_DOWN (M4) Coil uses the Latching function, the IR_GATE_OUT_DOWN (M4) Coil will remain active even though the SENS_CAR_OUT2 (I0.6) contact has been Disabled. When the LS_GATE_OUT_DOWN (I0.10) contact is Active, the IR_GATE_OUT_DOWN (M4) coil will be Disabled.