Street Light Control Based on Light Intensity

This article discusses an automatic street lighting system based on Siemens TIA-Portal. The system can control the on/off status of the lights based on light intensity levels (lumens) or the presence of vehicles and pedestrians. The goal is to enhance energy efficiency and improve road safety. This system utilizes a comparator function to control the lighting by comparing the actual light intensity (PV) with the minimum light intensity threshold (SV).

Contents

Program Objective

Street Light Control Based on Light Intensity – Siemens PLC

Mode Selection:

Set the selector switch to the “Normal” or “Power Saving” position to select the desired mode.

Normal Mode:

Light Measurement: The light sensor measures the surrounding brightness level in real-time.

Lumen Level: The light level is measured in lumens.

Light Adjustment:

If the lumen is less than 30: All 4 lights turn On.
If the lumen is between 31-60: 2 lights turn On.
If the lumen is between 61-120: 1 light turns On.

Power Saving Mode:

Sensor Activation: The lights are activated by a PIR sensor that detects vehicle or pedestrian movement.
Individual Sensors: Each light (total of 4 lights) has its own motion/PIR sensor.
On-Demand Lighting: The lights only turn on when the sensor detects movement.

Mapping Details

S.No.	Comment	Input (I)	Output(Q)	Memory Word	Memory Bit	Timer
1	PB_START	I0.0
2	PB_STOP	I0.1
3	NORMAL_OR_SAVING	I0.2
4	PIR_SENS1	I0.3
5	PIR_SENS2	I0.4
6	PIR_SENS3	I0.5
7	PIR_SENS4	I0.6
8	LAMP1		Q0.0
9	LAMP2		Q0.1
10	LAMP3		Q0.2
11	LAMP4		Q0.3
12	LUMENS_PV			MW2
13	SYSTEM_ON				M0.0
14	IR1_PIR1				M0.1
15	IR1_PIR2				M0.2
16	IR1_PIR3				M0.3
17	IR1_PIR4				M0.4
18	IR_SAVING_1				M0.5
19	IR_SAVING_2				M0.6
20	IR_SAVING_3				M0.7
21	IR_TIMER1				M1.0

Street Light Control Based on Light Intensity

Street Light Automation using Siemens PLC

NETWORK 1 (START SYSTEM)

In this network, the memory bit SYSTEM_ON (M0.0) will be in the HIGH state when the PB_START (I0.0) button is Pressed. Even though the PB_START (I0.0) button has been Released, the memory bit SYSTEM_ON (M0.0) will remain in the HIGH state. Because it uses Latching.

The memory bit SYSTEM_ON (M0.0) will be in the LOW state if the PB_STOP (I0.1) button is Pressed.

NETWORK 2 (NORMAL MODE)

In this network, when the NO contact of the memory bit SYSTEM_ON(M0.0) is in the HIGH state and the value in the word memory LUMENS_PV (MW2) is Less Than or Equal to “30”, then the memory bit IR_SAVING_1 (M0.5) will be in the HIGH state.

When the NO contact of the memory bit SYSTEM_ON (M0.0) is in the HIGH state and the value in the memory word LUMENS_PV (MW2) is Less Than or Equal to “60” and Greater Than “30”, then the memory bit IR_SAVING_2 (M0.6) will be in the HIGH state.

When the NO contact of the memory bit SYSTEM_ON (M0.0) is in the HIGH state and the value in the memory word LUMENS_PV (MW2) is Less Than or Equal to “120” and Greater Than “60”, then the memory bit IR_SAVING_3 (M0.7) will be in the HIGH state.

And if the NC contact of the selector switch NORMAL_OR_SAVING (I0.2) is in the HIGH state, then the memory bits IR_SAVING_1 (M0.5), IR_SAVING_2 (M0.6), and IR_SAVING_3 (M0.7) will be in the LOW state.

Automatic Street Lighting with PIR Sensors

NETWORK 3 (SAVING MODE)

In this network, memory bit IR1_PIR1 (M0.1) will be in HIGH state if contact NO of memory bit SYSTEM_ON (M0.0), selector switch NORMAL_OR_SAVING (I0.2), and sensor PIR_SENS1 (I0.3) are in HIGH state.

The memory bit IR1_PIR2 (M0.2) will be in the HIGH state when the PIR_SENS2 (I0.4) sensor is in the HIGH state.

The memory bit IR1_PIR3 (M0.3) will be in the HIGH state, when the PIR_SENS3 (I0.5) sensor is in the HIGH state.

The memory bit IR1_PIR4 (M0.4) will be in the HIGH state, when the PIR_SENS4 (I0.6) sensor is in the HIGH state.

NETWORK 4 (LAMP 1)

If any of the NO contacts of the memory bits IR1_PIR1 (M0.1), IR_SAVING_1 (M0.5), or IR_SAVING_2 (M0.6) are in the HIGH state, then the LAMP1 (Q0.0) output will be ON.

NETWORK 5 (LAMP 2)

If any of the NO contacts of the memory bits IR1_PIR2 (M0.2), IR_SAVING_1 (M0.5), or IR_SAVING_2 (M0.6) are in the HIGH state, then the LAMP2 (Q0.1) output will be ON.

Siemens PLC Street Light Example Project

NETWORK 6 (LAMP 3)

If any of the NO contacts of the memory bits IR1_PIR3 (M0.3), IR_SAVING_1 (M0.5), or IR_SAVING_3 (M0.7) are in the HIGH state, then the LAMP3 (Q0.2) output will be ON.