TECO SG2 Series User manual

SG2 PLR Application Examples
SG2 Programmable Logic Relay

Application Illustration
1. Lighting Control for Staircase
1.1 Requirement for Staircase Lighting
yWhen someone goes up-stair or down-stair, the lighting system shall be energized to
provide sufficient luminance.
yAfter the walker passes the staircase, lighting system shall be turned off in five
minutes automatically or manually.
1.2 Traditional Lighting Control
There are two traditional controls available:
yApply pulse relay
yApply automatic timer to control the lighting system on the staircase
Components Applied
zSwitches
zAuto lighting system or pulse relay for staircase
Applying the pulse relay as controller for staircase lighting system
yThe lighting is on as long as any switch is turned on.
yPress any switch again to turn off the lighting system.
Shortcoming: It is a frequent weak point for the person to forget turning off the light at
most cases.
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Auto lighting control system for the staircase
yThe light is on whenever the switch is turned on.
yLighting system shall be turned off in a few minutes automatically or manually
Shortcoming: The user has no way to reset the turn-off time.
1.3 Apply SG2 in Lighting System
Devices Applied
zQ1 LampH1
zI1(No terminal) Switch B1
zI2(No terminal) Infrared sensor for climbing
Wiring Diagram for Lighting System
Illustrated program using SG2 in lighting system
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Ladder：
FUNCTION：
FBD：
2 Auto Door Control
The auto doors are very popularly installed at the entrance of supermarkets, mansions,
banks and hospitals.
2.1Requirement forAuto Door Control
yIt automatically opens whenever a person is approaching.
yThe door remains open for a certain period and closes if no visitor is present.
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2.2 Traditional solution
Whenever B1 or B 2 senses the approach of a visitor, the door is actuated to open. After an elapse
of time, B1 or B2 senses no presence of a visitor; MC 4 will close the door.
2.3 Apply SG2 in Door Control System
Applying SG2 in door control system can simplify the circuit. All that one need to do is
connect the action sensor, limit switch and contactor with SG2.
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Devices Applied
zMC1 main door open contactor
zMC2 main door close contactor
zS1(NC contact) closing limit switch
zS2(NC contact) opening limit switch
zB1(NO contact) outdoor infrared sensor
zB2(NO contact) indoor infrared sensor
Wiring Diagram and Program with SG2 applied in door control system.
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Ladder：
FUNCTION：
FBD Operation Flow：
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3. Ventilation Control
3.1 Ventilation System Requirement
The main function of the ventilation system is to blow in the fresh air and blow out the waste air
as shown in the below drawing
yThe room is provided with exhausted gas blower and fresh air blower
yThe flow sensor control the blowing in and out operation
yOver pressure is permitted at no time.
yThe fresh blower will run only if the flow monitor senses that the exhausted
gas blower works properly.
yIf any irregularity takes place on air in blower and air out blower, the warning
lamp will light.
The control circuit for the traditional ventilation system is shown below:
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The ventilation system is wholly controlled by the airflow monitor. If there is no flow air in the
room after a designated duration of time, the system will activate the warning system so the user
shall shut off the system.
Devices Applied
zMC1 main contactor
zMC2 main contactor
zS0(NC contact) stop switch
zS1(NO contact) start switch
zS2(NO contact) air flow monitor
zS3(NO contact) air flow monitor
zH1operation indicator
zH2 alarm light
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Wiring Diagram and Program with SG2 applied in Ventilation System.
Ladder：
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FUNCTION：
FBD Operation Flow：
4. Plant Gate Control
4.1 Requirements for Plant Gate Control
The main purpose of the plant gate is to control the access of truck, which is manually
operated by the gate guard.
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yThe door guard controls and oversees the opening, closing of the
plant door gate.
yThe stop switch can be activated at any time regardless of the gate
in fully open or close condition.
yThe alarm light will be activated for 5 seconds in advance before
the gate operation.
yThe damper is provided on the gate. Gate closing operation,
whenever the damper is contacted by the gate, stops.
4.2 Traditional Control Circuit for Gate System
Devices Applied
zMC1 Main Electromagnetic Contactor
zMC2 Main Electromagnetic Contactor
zS0(NC contact) stop switch
zS1(NO contact) open switch
zS2(NO contact) close switch
zS3(NC contact) open safe damper
zS4(NC contact) close safe damper
Wiring Diagram and Program with SG2 applied in Plant Gate
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Ladder：
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FUNCTION
FBD:
5．Counting Control for Packing Machine
Requirement：
1) The packing cycle is that it begins counting the finished products in the assemble
line, when the counting value reaches 12, it proceeds packing operation which
takes 5 seconds. After finished, it begins a new cycle.
2) It simultaneous counts the finished packs of product.
3) In case of power failure, the counting remains unchanged.
Analysis：
1) A transducer is employed to produce the pulse signal when the transducer
detects the arrival of a product. A counter generates an output when the counting
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value reaches 12 and a timer is employed to have a delay of five seconds.
2) The counter will be operated in mode 3 or mode 4 in an effort to keep the
accurate counting even in case of power failure.
Devices Applied
unting sensor;
S1：reset the counting value to zero;
MC1：packing
Wiring Diagram and Program with SG2 applied at for Packing Machine
I1：co
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Ladder：
FUNCTION：
FBD：
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