Door Interlock Control System

Chapter 1
COMPANY PROFILE
1.1 INTRODUCTION
E-park is based in Silicon Valley Bangalore, are a team of qualified professionals with
extensive industrial exposure that brings to you a mix of youth and experience, they offer Real-
time projects for final year technical students. They also offer guidance, workshops by Industry
experts. And they provide many more IT services.
They have successfully performed projects under various platforms and has delivered
high quality competitively priced products and services to customers all over India. They
specialize in designing network solutions and security systems to meet your individual business
requirements, through their initial concept.
They do their academic projects on embedded, Matlab, VLSI, Robotics, java, .net, PHP,
Linux. They also do their workshops on Basic electronics, Embedded Design, Hardware and
Networking, PCB designing, VLSI Design. They provide services on Embedded Design and
Development, PCB Design, Website Design and Hosting, Software Development.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 1

 Door Interlock Control System

1.2 PRODUCTS
1.2.1 Hasiru (GSM motor Controller)

Fig 1.1: Hasiru circuit board

Hasiru is a GSM based wireless 3-phase motor controller to operate field installed motors
remotely and in real time. Generally, a substantial amount of time and energy is spent by a
person to visit field for operating motors. The farmer/operator has to travel to fields often during
odd hours and in an unfavorable weather just to switch ON/OFF the motor due to unexpected
erratic power supply. They developed this GSM technology based wireless 3-phase motor
controller to operate 3-phase motor in timely manner and only when needed on real-time basis,
so saves large amount of energy, water and power.
1.2.2 Gas Leak Detector

Fig 1.2: Gas leak detector

The gas Leak detector has been developed for the purpose of detecting minute gas leaks
in and around the gas pipe lines. It is most useful for anyone working with flammable gases. It
shows accurate gas leak point in the gas line. You can use this Device to Check Gas leak as well
as for Alcohol Detection.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 2

 Door Interlock Control System

1.2.3 Street light timer

Fig 1.3: Belaku circuit board

Belaku the GSM Street Light Controller is specific energy conservation product designed
to employ in city, villages and colonies where energy saving & energy conservation is critical
issue. The GSM technology based wireless street light controller used to operate street light in
timely manner and only when needed on real-time basis, so saves large amount of energy and
power.
1.2.4 Door interlocking system

Fig 1.4: Circuit diagram of Door interlocking system

The door interlocking system is used to control the entry of personnel to a secure area
such as a clean room, where dust or small particles may be a problem. The principle is generally
well under-stood. In its simplest form, the door interlocking is composed of 2 to 12 doors that are
electrically interlocked in such a way that the all doors cannot be opened simultaneously. The
door interlocks are used in a variety of situations but in essence they are there to control the
unwanted passage from one area to another.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 3

 Door Interlock Control System

1.2.5 Power Transformers

Fig 1.5: Power transformer

A transformer is an electrical device that transfers electrical energy between two or more
circuits through electromagnetic induction. Electromagnetic induction produces an electromotive
force across a conductor which is exposed to time varying magnetic fields. Commonly,
transformers are used to increase or decrease the voltages of alternating current in electric power
applications.
1.2.6 LCD/LED TV Stsbilizer

Fig 1.6: LED/LCD TV Stabilizer

The LED/LCD TV is not the only electronic device in the house taking power. Every
time the AC comes on or the furnace starts, electricity is used. This causes temporary power dips
to other electronics, like the LED TV, which in turn affects the TV’s processes. In fact, one of
the reasons why many LED TVs fail early in life is not because of their display technology, but
instead because their power caps get busted from power surges or dips. Install a voltage regulator
with a battery backup that can provide additional power during dips. Not only will it protect
against hazards like power surges caused by lightning, it will help keep the TV operating
efficiently no matter what other electronics are being used in the home.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 4

 Door Interlock Control System

1.2.7 Home security systems

Fig 1.7: Home Security system

A security alarm is a system designed to detect intrusion unauthorized entry into a
building or area. Security alarms are used in residential, commercial, industrial, and military
properties for protection against burglary (theft) or property damage, as well as personal
protection against intruders. Car alarms likewise protect vehicles and their contents. Prisons also
use security systems for control finmates.
Some alarm systems serve a single purpose of burglary protection; combination systems
provide both fire and intrusion protection. Intrusion alarm systems may also be combined with
closed-circuit television surveillance systems to automatically record the activities of intruders,
and may interface to access control systems for electrically locked doors. Systems range from
small, self-contained noisemakers, to complicated, multi-area systems with computer monitoring
and control.
1.3 TOOLS USED IN THE ORGANIZATION
As e-park research center is embedded development company, different tools are used.
Tools are listed below
● Keil -5
● Microchip
● Arduino IDE
● Flow code-4
● Orcad-16.1
● Putty serial communication software
● XCT-U serial communication software
● Flash magic

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 5

 Door Interlock Control System

● Nuvoton flasher
● Proload for ATMEL
Micro controllers used in e-park
● ARM-7
● P89v51rd2
● AT89s52
● Nuvoton
● Renesis
● Arduino mega
● Raspberry pie-3
Technology used in e-park research center
● IoT
● GSM
● ZIGBEE
● Bluetooth/wifi
● RF wireless technology
● Wireless sensors network
1.4 ORGANIZATION STRUCTURE
e-park is one of the best design and development start-up company in Banglore, e-park is
active in many sectors, its core businesses being in power saving and automation technologies.It
also working in IT support and corporate trainings.
Different Departments in Company
E-park research center has following departments
● Department of Research and development
● Department of Production and QC
● Department of Project training
● Department of Corporate training
● Department of IT services
● Department of Marketing and service
● Department of Admin and accounts
1.4.1 Department of Research and Development

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 6

 Door Interlock Control System

e-park has a very good and qualified R&D team. The size of the R&D team is four. They
work on new innovative things and develop the new products also work on the existing product
for up gradation. e-park research center takes embedded projects from various industrial clients
and they will design and develop the projects in accordance with client’s requirements.
1.4.2 Department of Production and QC
e-park research center produces various products, e-park has good skilled and qualified
production team. The production team size is five also it has one Quality controller. Every
product manufactured in the e-park will gone through the quality test.
1.4.3 Department of Project Training
With the intension of filling the gap between industrial requirements and present
technical education e-park started an academic projects trainings. In this department students will
come with their own innovative ideas, e-park will guide them in a right way to implement the
idea .e-park has good skilled and qualified project trainers. the team size is four. Even R&D team
will take care of the project development and training. Some projects will be developed by the
industrial freelance developers e-park is training the students in different platform e.g.,
embedded system, VLSI, Image processing, JAVA, web development, IoT, HTML,PHP, Cloud
computing etc.
1.4.4 Department of Corporate Training
Corporate companies are offered jobs for well skilled person. so e-park research center
offers corporate trainings for qualified engineers and help them to achieve their dreamed job.
Project development team will handle this corporate training also.
1.4.5 Department of IT Services
e-park also deals with following IT services with our co-company “G-mindz Infotech” support
● Computer hardware and networking
● Security system
● On demand services
● Cloud telephone services
● AMC service

1.4.6 Department of Marketing and Services

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 7

 Door Interlock Control System

Marketing and service department very essential department in every organization. By

having well skilled marketing and service team an organization can reach the market. e-park has
very skilled and qualified marketing and service team. The team size is four. These four people
will not resides in the office, they will be always in field.
1.4.7 Department of Admin and Accounts
Admin and account departments are take care of the purchase, sales, accounts and all in
& outs of the company. e-park has one admin and accountant. They are working for e-park
growth in all dimensions.
1.5 COMPANY CLIENTS
e-park manufactures electronics products for domestic users and agriculture products for
farmers so farmers and domestic users also clients for e-park. Apart from that as e-park is a start-
up company it has few clients, Clients list is below
● Relon Trading limited: Relon is marketing based company located at Richmond
road Bangalore. e-park developed and manufacturing a gas leak detector for Relon since
2014.
● Dastu electricals: Dastu electricals is service based company located at Verna-Goa.
e-park developed various access control systems for farm city or medical manufacturing
industries in the name of Dastu electricals.
● G-mindz InfoTech: G-mindz InfoTech is a IT supporting organization located at
Rajrajeshwari nagar Bangalore, They are official channel partners for all e-park
products.
● CN enterprises: CN enterprises is a leading power transformer and stabilizer
manufacturers located at Rajajinagar Bangalore, e-park is taking care of R&D for CN
enterprises.

Chapter 2

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 8

 Door Interlock Control System

DOOR INTERLOCK CONTROL SYSTEM

2.1 INTRODUCTION
Quite often one of the requirements of clean room technology or laboratories is that
certain doors may only be opened if others are closed. The Industrial access control system is the
ideal solution to link up to 10 doors or up to 10 groups of doors (each with 10 doors maximum).
The dependencies between different doors are programmed directly in the control modules on
each door with DIP-switches, using a very easy, adjustablematrix control system. The
dependencies between the doors can also be changed on site at any time, not requiring any
special programming know-how. The interlock control terminal disposes of a potential-free
contact permitting e.g. to pass on the information of each door to a central control system. The
Industrial access control system is a modular system and therefore extremely flexible. All
components are provided with a plug-in connection, which considerably reduces installation
costs. The system also provides a tested and approved terminal for emergency exit doors .The
system is also available in an explosion-proof execution.

2.2 ACCESS CONTROL SYSTEM

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 9

 Door Interlock Control System

The interlock control system is designed for a maximum of 10 doors or 10 groups with
each 10 doors at most. A very simply to adjust matrix control permits to determine the link
between the different doors on site. And also to change the links and dependencies later on. If the
interlock unit consists of less than 10 doors/groups, the remaining DIP-switches are just not used.
These units can however be enlarged later on to the maximum of 10 doors/groups without having
to change the interlock control terminals on the existing doors. The dependencies between the
different doors of the unit are set with 10 DIP switches per door. A potentiometer permits to
adjust on each door a time during which it remains unlocked after the push button has been
pressed (0 - 30 sec). This determines the time within which the door has to be opened after
having pressed the push button of the terminal. When this time has elapsed the door will be
locked again. It is of no significance whether the door has really been opened or not. The period
of time to adjust depends amongst others e.g. on the use of the door: interlock systems for
material or persons.

Fig 2.1: Access control system

2.3 INDICATION OF THE DOOR STATUS (UNLOCKED OR LOCKED)

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 10

 Door Interlock Control System

Status is realized by an illuminated ring around the push button:

Green illumination: Door is locked but can be opened using the push button of the
terminal.
Red illumination: Door is locked. It cannot be opened as it is blocked by another opened
door. The illumination of the ring will return to green as soon as the other door(s) is (are) closed
again.
2.4 EMERGENCY-OPEN SWITCH
Part of the terminals is equipped with an additional emergency open switch. In case of an
emergency the door can be unlocked with help of the Emergency-Open switch even while being
locked by the interlock control system. The switch remains locked after having been pressed. In
order to reactivate the interlock control system the emergency-open switch has to be unlocked by
turning. After a short delay the system is ready to work again. There are two different
emergency-open functions possible: - Local emergency open (LNA): only the door of the
respective terminal will be unlocked. - Global emergency open (GNA): it unlocks all doors of the
interlock system. The function is determined by the wiring of the terminals. Therefore the
required function of the emergency-open switch has to be taken into account when deciding on
the connection cables. IMPORTANT: The emergency-open switch of the terminals can only
switch 24 VDC. If the emergency-open switch should switch off e.g. a 230 VAC door operator a
separate switch is required.

2.5 INTERLOCK CONTROL SYSTEM - COMPONENTS

Interlock control terminals with push button and (if necessary)
2.5.1 Emergency-Open Switch:
For each door one interlock control terminal is required. There the dependencies with the
other doors of the interlock system are adjusted with DIP-switches on the circuit board.
Furthermore there is the potentiometer to determine the duration of unlocking (0 - 30 sec.) and
the potential-free make/break contact. The control circuit board is fixed as a kind of back pack to
the front plate of the control terminal. The connection cables are simply plugged in.

2.5.2 Operating terminals:

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 11

 Door Interlock Control System

Normally an additional operating terminal is required for the opposite side of the door.
This consists either just of the push button or the push button and the Emergency-Open switch.
2.5.3 Emergency exit terminal:
The emergency exit terminal has to be used on emergency exit doors in combination with
a control terminal without Emergency-Open switch. It has been tested and is approved according
to the German standard for emergency exits.
2.5.4 Connection cables:
The connection of the terminals and the locking units is done with prefabricated cables
with connector. They are available in different lengths.
Distribution box: For each door one distribution box is being required. There is a plug-in
connection provided for the cables (12 VDC supply and trip line) to the control terminal. For the
wiring between the distribution boxes normal binders are provided.
2.5.5 Central power pack:
The 12 VDC power supply of the terminals and the locking units is assured by a central
power pack. It is available either with a 2.7 A or 5 A power supply, depending on the
components used in the interlock unit and their power consumption.
2.5.6 Locking element:
The doors of the interlock unit should be locked with the electronic bar magnets with
600Lbs.
2.5.7 Special functions:
● Time control unit provides a special time control unit in order to adjust lock times for
each single interlock door (e.g. in case of decontamination interlocks).
● Additional relay controlled functions It is possible to provide sockets for plug-in relays in
the distribution boxes in order to realize special functions.
● Interface An interface permits the connection of the interlock system to a facility
management system. This permits to channel the information on the doors (closed,
locked, unlocked) to a central system and to forward signals vice versa. The
communication software has to be provided by the customer.

2.6 INTERLOCK CONTROL SYSTEM CONTROL TERMINALS

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 12

 Door Interlock Control System

The control terminal is the central component of the DICTATOR interlock control
system, being the component with the control circuit board on which the dependencies between
the different doors are set. There are different models of the control terminal available: - with
and without an Emergency-Open switch - for installation in hollow profiles or for universal
installation The DICTATOR terminals meet the requirements of cleanroom technology. As push
button a special peso-type key is used that reacts on very little pressure. The push button is
surrounded by an illuminated ring, one half red, the other half green. Both front plate and push
button are made of stainless steel.

Fig 2.2: Control terminal(a)

● Control terminals for hollow profiles "P" (narrow front plate) - Control terminal ST P,
part no. 710800 Description: Control terminal with emergency-open switch and push
button - Control terminal ST on P, part no. 710802 Description: Control terminal with
push button, without emergency-open switch
● Control terminals for universal installation "U" (wide front plate) - Control terminal ST
U, part no. 710825 Description: Control terminal with emergency-open switch and push
button - Control terminal ST on U, part no. 710827 Description: Control terminal with
push button, without emergency-open switch All control terminals are provided with a

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 13

 Door Interlock Control System

potential-free contact in order to pass on the information on the status of the door
(open/locked) to a facility control system.2.6 Interlock Control System Control Terminals

Fig 2.3:Control terminal(b)

The control terminal is the central component of the DICTATOR interlock control
system, being the component with the control circuit board on which the dependencies between
the different doors are set. There are different models of the control terminal available: - with
and without an Emergency-Open switch - for installation in hollow profiles or for universal
installation The DICTATOR terminals meet the requirements of cleanroom technology. As push
button a special peso-type key is used that reacts on very little pressure. The push button is
surrounded by an illuminated ring, one half red, the other half green. Both front plate and push
button are made of stainless steel.
● Control terminals for hollow profiles "P" (narrow front plate) - Control terminal ST P,
part no. 710800 Description: Control terminal with emergency-open switch and push
button - Control terminal ST N P, part no. 710802 Description: Control terminal with
push button, without emergency-open switch
● Control terminals for universal installation "U" (wide front plate) - Control terminal ST
U, part no. 710825 Description: Control terminal with emergency-open switch and push
button - Control terminal ST N U, part no. 710827 Description: Control terminal with
push button, without emergency-open switch All control terminals are provided with a
potential-free contact in order to pass on the information on the status of the door
(open/locked) to a facility control system.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 14

 Door Interlock Control System

2.7 TECHNICAL DATA

Power consumption 12 VDC +/- 15 %

with emergency-open switch 50 mA

without emergency-open switch 40mA

IP rating IP 20 (push button IP 65)

Capacity of the potential-free contact make/break, max. 1.5 A at 60 VAC/D

Operating temperature -10 °C to +40 °C

Push button Peso type with red/green illumination

Capacity of the emergency-open 1 contact NO: 1.5 A; 1 contact NC: 2.8 A
switch
` Emergency open switch push-to-lock switch

Table 2.1: Technical data

2.8 ACCESS CONTROL SYSTEM - OPERATING TERMINALS

Normally the doors of an interlock system are operated from both sides. Therefore an
additional operating terminal (without control board) connected to the control terminal is
required on the other side of the door. The operating terminal is connected to the control terminal
quite easily with a plug-in cable. This is available in 2 lengths: 250 mm and 1000 mm. The
connection cable must be ordered separately.
● Operating terminals for hollow profiles "P" (narrow front plate) - Operating terminal BT
P, part no. 710801 Description: Operating terminal with emergency-open switch and push
button - Operating terminal BT on P, part no. 710803 Description: Operating terminal
with push button, without emergency-open
● Operating terminals for universal installation "U" (wide front plate) - Operating terminal
BT U, part no. 710826 Description: Operating terminal with emergency-open switch and
push button - Operating terminal BT on U, part no. 710828 Description: Operating
terminal with push button, without emergency-open

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 15

 Door Interlock Control System

Fig 2.4: Operating terminal(a)

Fig 2.5: Operating terminal(b)

2.9 INTERLOCK CONTROL SYSTEM - EMERGENCY EXIT TERMINAL

The DICTATOR interlock control system provides a terminal designed especially for
doors in emergency exits. These doors are equipped both with the normal control terminal and an
additional emergency exit terminal. This terminal only serves for unlocking the door during an
emergency. The normal operation of the interlock system is done with the control terminal
(without Emergency-Open switch). The emergency exit terminal has been tested by the German
TÜV Thüringen and is approved for the use on emergency exit doors (German standard for
electrical locking systems on emergency exits), certificate no. P-3250/08.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 16

 Door Interlock Control System

Fig 2.6: Emergency exit terminal

2.9.1 Functioning:
The emergency-open switch of the emergency exit terminal permits to unlock the door of
the interlock system in case of an emergency. The locking unit has to be an approved electronic
bar magnet (starting on page 08.015.00, approved magnets marked with *). The power supply of
the bar magnet is interrupted and the door unlocked. The emergency exit terminal is provided
with contacts for external signals (siren, lamp, horn), even supplying a power of up to 1.4 A max.
for the signal (ATTENTION: this power consumption has to be taken into account when
calculating the required performance of the power pack). The emergency-open command can
also be given directly by a facility management center.
The door status is indicated by the two lamps on the terminal:
Red LED on: Door is electrically locked. Red LED off: Door has been opened with the
normal control/operating terminal.
Green LED on: Door is released. After an emergency the door has to be locked again with
a separate key (key switch, card reader or similar).

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 17

 Door Interlock Control System

2.9.2 Technical Data:

Power consumption 12 VDC

with emergency-open switch About 80 mA
without emergency-open switch About 70mA
IP rating IP 20
Capacity of the potential-free contact make/break, max. 1.5 A at 60 VAC/D

Operating temperature -10 °C to +40 °C

Emergency open contact 2 NC contacts: 2.8 A (current carrying

capacity)
Input signal from hazard alert system NC contact Output to signals 24 VDC, max.
1.4 A T
Table 2.2: Technical data

2.10 INTERLOCK CONTROL SYSTEM-INSTALLATION COMPONENTS

The majority of the interlock system components are connected with prefabricated cables
with connector. This reduces the installation work and avoids mistakes while connecting the
components. Each door of the interlock system must be equipped just with the required terminals
and a locking unit. Further push buttons/switches are not required. This reduction to just a few
components also facilitates cleaning in cleanroom areas.
Normally one distribution box, part no. 710807, is used per door. There the loop cable (to
be provided by the customer) connecting all doors of the interlock system is connected. The
quantity of leads of this cable depends on the number of doors within the interlock system. In
addition to the 24 VDC power supply (2 leads) one lead (diameter 0.5 mm2) per door is required.
Dimensions: 160 x 86 x 130 mm If two doors are situated right beside another, a distribution
boxfor 2 doors is available (part no. 710821). The distribution box can also be furnished with
additional relays permitting the realization of special functions. The control terminals are
connected to the distribution box with the prefabricated connection cables. Normally the
terminals are flush mounted in the frames of the doors.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 18

 Door Interlock Control System

Fig 2.7: Installation components

e-park provides flush boxes for both models "P" and "U" (part no. 710829 and 710830). In case a
flush mounting is not possible there is a special surface box available for the "P" model. The
surface box has IP 65 protection and can be supplied in two different colors: - white, RAL 9010
(part no. 710831) - black, RAL 9005 (part no. 710832) As the dimensions of the emergency exit
terminals differ a littlebit from those of the normal terminals you need special flush and surface
boxes.The part numbers and types you will find on page 08.012.00.
Connection Cables:
Plug-in connection cable control/operating terminal The connection cable between control
and operating terminal is a plug-in cable with connector on both ends. It is available in
twolengths: 250 mm (part no. 710809) and 1000 mm (part no. 710810). It always has to be
ordered separately in addition to the control terminal - if the door is equipped with a control and
an operating terminal. In case that a connection cable with a different length is required it can be
done on site. However a set of adapters has to be ordered (part no. 710811) as the terminals
require a special connector.
Dummy plug for the control terminal - for stand-alone function If a door is equipped only
with a control terminal without an additional operating terminal on the other side of the door, a
dummy plug must be placed on the connector where normally the connecting cable to the
operating terminal would be plugged in (part no. 710812). Connecting cables for the control
terminal ST (P/U) The connecting cables serve two purposes: connection of the control terminal
to the distribution box (24 VDC power supply and trip line) and to the locking unit on the door.
These connection cables are available in three lengths: 3 m, 5 m, 10 m Important: the length of
the cable to the locking unit is always just 2 m. Before choosing the connecting cables the

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 19

 Door Interlock Control System

required Emergency-Open function must be decided on: either local Emergency Open (LNA) or
global Emergency Open (GNA) (see page 08.004.00) as these are realized by a different set of
cables (part nos. 710814 - 710816 or 710818 - 710820).
Set of connection plugs for individual wiring:
If the above mentioned connection cables are not used, a set (4 pcs.) of connection plugs
(part no. 710817) is required in order to be able to make the connections with a normal cable.
The terminals dispose only of plug-in positions (sockets) and not of feeder clamps.
Connection cable for access controls or large-surface switches:
This connection cable is also just plugged into the control terminal. At the other end of
the cable are free leads with end sleeves. Length: 2 m (part no. 710813)
2.11 Interlock Control System - Time Control Unit
Some interlock systems require that some doors only open after a certain time delay, e.g.
if the quality/temperature of air in the interlock must reach a certain level before the door to the
cleanroom may open. The DICTATOR time control unit permits the blocking of max. Clean
room doors against up to 6 "black room" doors. If one or several of the "black room" doorsare
opened during the locking time, the time control unit starts the count-down again. Only when the
adjusted time has elapsed, the door to the cleanroom can be opened.

Fig 2.8: Time control unit

2.11.1Functioning / Dimensions:
The type of door (cleanroom or black room) is determined by the connection of the cables from
the control terminals to the time control unit. The required time lag (16 different values possible) is
adjusted in the time control unit with the help of 4 DIP-switches. If a time different from the 16 adjusted
time lags is required, this has to be indicated in the order as it has to be programmed in production. The

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 20

 Door Interlock Control System

time control unit has a 7-segment display and an additional dot. If the time control unit is on, the dot of
the display lights up. When the time control unit is activated by one of the connected terminals, the dot
starts flashing (one flash per second). When all black room doors are closed the time countdown starts.
The time control unit divides the adjusted time into 10 intervals and the display counts down from 9 to 0,
thus indicating the remaining time during which the doors stay locked.
2.11.2 Models / Components
It is possible to connect up to 6 additional displays (part no. 710805) to the time control
unit. Independent of the amount of additional displays there is always required one extender
circuit module (part no. 710808). The time control unit is connected with a normal cable to
thedistribution box (see page 08.009.00). For the connection of the additional displays and the
extender circuit module the connection cables, part no. 710809 or 710810, are to be used. If their
length is not sufficient, the connection has to be done on site. In this case a set of connection
plugs, part no. 710 811, is required, one for each additional display.
2.11.3 Technical Data
max. 20 mA Power consumption extender circuit module 24 VDC, max. 2 mA Power
consumption additional display 24 VDC, max. 10 mA IP rating IP 20 Operating temperature -10
°C to +40 °C Time lags 16 different time lags adjustable (0, 15, 20, 25, 30, 35, 40, 50, 60, 120,
180, 240, 300, 420, 540, 660 seconds) max. time lag 2,75 hours Quantity of connectable doors 6
cleanroom and max. 6 "black room" doors
Power consumption 12 VDC

with emergency-open switch About 20 mA

without emergency-open switch About 20mA

IP rating IP 20
Capacity of the potential-free contact make/break, max. 1.5 A at 60 VAC/D

Operating temperature -10 °C to +40 °C

Emergency open contact 2 NC contacts: 2.8 A (current carrying

capacity)
Table 2.3: Technical data

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 21

 Door Interlock Control System

2.12 INTERLOCK CONTROL SYSTEM - ORDER INFORMATION

Operating terminal BT P Part no. 710801 Operating terminal BT on P without emergency-

open switch Part no. 710803 Operating terminal BT U Part no. 710826Operating terminal BT on
U without emergency-open switch Part no. 710828 Emergency-exit terminal FT P (see page
08.014.00) Part no. 710833 Control terminal ST P Part no. 710800 Control terminal ST on P
without emergency-open switch Part no. 710802 Control terminal ST U Part no. 710825 Control
terminal ST on U without emergency-open switch Part no. 710827 Order Information Control
Terminals (see page 08.006.00) On this page you will find a summary of the part numbers of all
components described on the previous pages (see summary of the main components on page
08.005.00). For information regarding the power packs please see page 08.039.00 and following
pages. The doors of the interlock system can be locked either with the DICTATOR door lock
TVR (see page 08.029.00) or a DICTATOR bar magnet (from page 08.015.00 on). When
choosing the bar magnet make sure to select a 24 VDC magnet with a feedback contact.
2.13 INTERLOCK CONTROL SYSTEM - SETTING OF THE DEPENDENCIES
The following matrix helps you to determine the position of the DIP-switches in the
control terminal on each door. Just mark for each door which other door(s) may be open at the
same time and which one(s) must stay locked (see example below). There are 3 positions for the
DIP-switches: Position +: determines the door for which the dependencies are decided (base
door) Position -: this door is locked as long as the "base door" is open. Position 0: this door can
be opened even though the "base door" is open as well.

Fig 2.9:
Setting of the

dependencies

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 22

 Door Interlock Control System

Chapter 3
TASKS PERFORMED
DOOR INTERLOCK CONTROL SYSTEM
The requirements of industrial technology or laboratories is that certain doors may only
be opened if others are closed.The Industrial access control system is the ideal solution to link up
to 10 doors.The dependencies between different doors are programmed directly in the control
modules on each door with DIP-switches .
3.1 BLOCK DIAGRAM

Fig 3.1: Exiting system single door interlock system

In this system use AT89C2051 microcontroller.relay is used to open or close the
electromagnetic lock by switching the voltage to ground and vcc respectively. The ULN driver is
used to drive relay and buzzer .when entrance/exit switch is used to controll the relay. When
entrance/exit switch is pressed to open and close of eletromagnetic lock then green indicator will
glow.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 23

 Door Interlock Control System

Emergency switch is pressed red indicator will glow.mode switch is used change the
mode.the same system is place another side Tx and Rx is used access the that by mode switch
hence another door can also controll using relay.
3.2 PROPOSED SYSTEM

Fig 3.2: Proposed system for four door interlock system

Using this system we can access the four door at a time. The proposed system working
principle same as exiting system. The entrance/exit switch 1 is press the electromagnetic lock 2
will be close and electromagnetic lock 1 will be open and green indicator will glow. When we
press entrance/exit switch 2 electromagnetic lock 2 will be open with respectively
electromagnetic lock 1.when emergency switch is press both the door will open irrespectively.
3.3 ABOUT AT89c2051
The AT89c2051 is a low-power, high-performance CMOS 8-bit microcontroller with 8K
bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s
high-density nonvolatile memory technology and is compatible with the industry-standard 80C51

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 24

 Door Interlock Control System

instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed
in-system or by a conventional nonvolatile memory pro-grammar. By combining a versatile 8-bit
CPU with in-system programmable.
Flash on a monolithic chip, the Atmel AT89c2051 is a powerful microcontroller, which
provides a highly flexible and cost-effective solution to many, embedded control applications.
The AT89c2051 provides the following standard features: 8K bytes of Flash, 256 bytes of
RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector
two-level interrupt architecture, a full duplex serial port, on chip oscillator, and clock circuitry.
In addition, the AT89c2051 is designed with static logic for operation down to zero
frequency and supports two software selectable power saving modes. The Idle Mode stops the
CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue
functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator,
disabling all other chip functions until the next interrupt

Fig.3.3: AT89c2051 kit

3.4 Brief Introduction to 8051 Microcontroller
The hardware is driven by a set of program instructions, or software. Once familiar with
hardware and software, the user can then apply the microcontroller to the problems easily.
The following are some of the capabilities of the 8051 microcontroller.
● Internal ROM and RAM
● I/O ports with programmable pins
● Timers and counters
● Serial data communication

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 25

 Door Interlock Control System

Fig 3.4.1: General Block Diagram of Microcontroller

The pin diagram of the 8051 shows all of the input/output pins unique to
microcontrollers:

Fig 3.4.2: 8051/8031 Pin Diagram

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 26

 Door Interlock Control System

The 8051 architecture consists of these specific features:

● 16 bit PC &data pointer (DPTR)
● 8 bit program status word (PSW)
● 8 bit stack pointer (SP)
● Internal ROM 4k
● Internal RAM of 128 bytes.
● 4 register banks, each containing 8 registers
● 80 bits of general purpose data memory
● 32 input/output pins arranged as four 8 bit ports: P0-P3
● Two 16 bit timer/counters: T0-T1
● Two external and three internal interrupt sources Oscillator and clock circuits.
3.5 SOFTWARE USED
3.5.1. Keil u-Vision 3.0
Keil Software is used provide you with software development tools for 8051 based
microcontrollers. With the Keil tools, you can generate embedded applications for virtually every
8051 derivative. The supported microcontrollers are listed in the μ-vision3.1.5 Keil Arm μ
Vision is a window-based software development platform that combines a robust and modern
editor with a project manager and make facility tool. It integrates all the tools needed to develop
embedded applications including a C/C++ compiler, macro assembler, linker/locator, and a HEX
file generator. The μ Vision IDE and Debugger is the central part of the Keil development tool
chain and has numerous features that help the programmer to develop embedded applications
quickly and successfully. The Keil tools are easy to use, and are guaranteed to help you achieve
your design goals in a timely manner.
3.5.2 Embedded C program using Keil u-Visionsoftware
Example 1. Blinking of LED
#include<reg51.h>
void delay(unsigned int xyz)
{
inta,b;
for(a=0;a<=xyz;a++)
{
for(b=0;b<=xyz;b++);
}
}

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 27

 Door Interlock Control System

void main()
{
while(1)
{
P0=0xFF;
delay(200);
P0=0x00;
delay(200);
}
}

Example 2. Rotating the shaft of the motor

#include<reg51.h>

sbit sw2 = P0^4;

sbit sw3 = P0^5;
sbit motor = P2^4;

void delay(unsigned int xyz)

{
inta,b;
for(a=0;a<=xyz;a++)
{
for(b=0;b<=500;b++);
}
}

void main()
{
P2=0X00;
P0=0X00;
sw2=1;
sw3=1;
motor=0;

while(1)
{
if(sw2 == 0)
{
motor=1;
delay(1000);
}
else if (sw3 == 0)
{
motor=0;
delay(1000);

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 28

 Door Interlock Control System

}
}
}
Example 3. Display of string on LCD

#include<reg51.h>
#define LCDPORT P1
sbit RS = P3^5;
sbit EN = P3^4;
void delay(unsigned int temp)
{
inti,j;
for(i=0;i<=temp;i++)
{
for(j=0;j<=10;j++);
}
}

voidlcd_cmd(unsigned char cmd)

{
LCDPORT = cmd;
RS = 0;
EN=1;
delay(50);
EN=0;
delay(50);
}
voidlcd_data(unsigned char dat)
{
LCDPORT = dat;
RS = 1;
EN=1;
delay(50);
EN=0;
delay(50);
}
lcd_string(unsigned char *ch)
{
{
while(*ch)
{
lcd_data(*ch);
*ch++;
}
}
}
lcd_string1(unsigned char *ch)

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 29

 Door Interlock Control System

{
{
while(*ch)
{
lcd_data(*ch);
*ch++;
}
}
}
void main()
{
lcd_cmd(0x38);
lcd_cmd(0x06);
lcd_cmd(0x0c);
lcd_cmd(0x80);
lcd_cmd(0x01);
lcd_cmd(0xC0);
delay(50);
lcd_cmd(0xC0);
lcd_string("praveen");
lcd_cmd(0xC10);
lcd_string("praveen");
lcd_cmd(0x80);
lcd_string1("praveen");
while(1);
}

Example 4. Serial communication for receiving and transmitting of data

#include<reg51.h>
unsigned char action;

voidsend_char(unsigned char ch)

{
while(TI==0);
SBUF=ch;
TI=0;
}
unsigned char reci(void)
{
unsigned char temp;
while(RI==0);
temp=SBUF;
RI=0;
return temp;
}

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 30

 Door Interlock Control System

void main()
{
unsigned char action;
SCON=0x50;
TMOD=0X20;
TH1=0XFD;
TR1=1;
TI=1;

while(1)
{
action = reci();
send_char(action);
}

3.6 FLASH MAGIC

Flash Magic is loaded being performed. This means that other applications that need to
use the COM Port, such as debugging tools, may be used while Flash Magic is Windows
software from the Embedded Systems Academy that allows easy access to all the ISP features
provided by the devices Flash Magic provides a clear and simple user Under Windows, only one
application may have access the COM Port at any one time, preventing other applications from
using the COM Port. Flash Magic only obtains access to the selected COM Port when ISP
operations are being performed. This means that other applications that need to use the COM
Port, such as debugging tools, may be used while Flash magic is loaded. To download the hex
file into the microcontroller board we use a programmer called flash magic tool.
3.7 NUVOTON
It is a console based tool which supports ICP (In-Circuit Programming) functions. Users
can use it to erase, program, or dump data on any NuMicro Family devices.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 31

 Door Interlock Control System

Following steps are used to dump the programs to microcontroller:

Step 1: Insert NUVOTON W78E052DDG Chip to 8051 RS232 Flasher Board and connect to
PC via RS232 Port.

Step 2: Install and Open Nuvoton ISP-ICP Utility IAP.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 32

 Door Interlock Control System

Step 3: Click ISP by COM Port and Select CHIP type and COM port.Remaining Unchanged.

Step 4: Click Load File and Select HEX File.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 33

 Door Interlock Control System

Step 5: Click Update Chip and press and Release RESET Button in 8051 RS232 Flasher Board.

Step 6: HEX Code Download Finish.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 34

 Door Interlock Control System

3.8 HARDWARE REQUIRED TO EXECUTE THE PROGRAM

Controller Unit: 8051 12C PRO-0, Features of 8051 Starter Kit (as shown in fig. 3.8)
● 8051 - 40 Pin DIP ( Nuvoton and SST chips used )
● 16 x 2 Alphanumeric LCD and trimmer for contrast Control.
● On Board RTC 1307
● On Board EEprom 24Cxx
● On Board ADC, DAC PCF8591 I2C Based
● RS232 Port
● On Board Regulated Power Supply

Fig. 3.8: 8051 12C PRO-0

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 35

 Door Interlock Control System

Chapter 4
DOOR INTERLOCK CONTROL SYSTEMS
4.1 HARDWARE COMPONENTS OF DOOR INTERLOCK CONTROL SYSTEM

Fig.4.1: shows hardware components used in the door interlock contol system.
DESCRIPTION OF EACH COMPONENT AS FOLLOWS:
Component No.1.PBT 2or 3 pin connector: 2 or 3 Pin, Screw type PCB Terminal Block,
generally used for power connections on a circuit board. Owing to high mechanical strength, heat
resistance upto 150degC and noncombustible nature of the PBT (Polybutylene terephthalate)
material, the connector is also strongly recommended for connections that require high degree of
electrical insulation.
Component No.2 Bridge rectifier: It is an arrangement of four or more diodes in
a bridge circuit configuration which provides the same output polarity for either input polarity. It
isused for converting an alternating current (AC) input into a direct current (DC) output.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 36

 Door Interlock Control System

Component No.3. ULN2003A:The ULN2003A is an array of seven NPN Darlington

transistors capable of 500mA, 50V output. It features common-cathode flyback diodes for
switching inductive loads. A Darlington transistor (also known as Darlington pair) achieves very
high current amplification by connecting two bipolar transistors in direct DC coupling so the
current amplified by the first transistor is amplified further by the second one. Typical usage of
the ULN2003A is in driver circuits for relays, lamp and LED displays, stepper motors, logic
buffers and line drivers.
Component No.4.Relay: It is an electrically operated switch. Many relays use
an electromagnet to mechanically operate a switch, but other operating principles are also used,
such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate
low-power signal, or where several circuits must be controlled by one signal.
Component No.5.Buzzer or beeper: It is an audio signalling device, which may be mechanical,
electromechanical, or piezoelectric. Typical uses of buzzers and beepersinclude alarm devices,
timers, and confirmation of user input such as a mouse click or keystroke
Component No. 6. Capacitors: These are components that are used to store an electrical charge
and areused in timer circuits. A capacitor may be used with a resistor to produce a timer.
Component No. 7. Crystal Oscillator: It is an electronic oscillator circuit that uses the
mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal
with a precise frequency.
Component No. 8 Microcontroller 2051: It is a 20 pin version of the 8051. It is a low-voltage,
high-performance CMOS 8-bit microcomputer with 2K bytes of Flash programmable and
erasable read only memory. Atmel manufactures the chip using high-density nonvolatile memory
technology. The 2051 and is compatible with the industry-standard MCS-51 instruction set. By
combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel 2051 is a powerful
microcontroller. It provides a very flexible, cost-effective solution to many embedded control
applications.
Operational features of the 2051:
The 2051 features Compatibility with MCS-51 ™ Products, 2K Bytes of
Reprogrammable Flash Memory with 1,000 Write/Erase Cycles. The operating range of the 2051
is 2.7V to 6V. Among these features, the 2051 also contains the following features:
● Fully Static Operation: 0 Hz to 24 MHz

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 37

 Door Interlock Control System

● Two-level Program Memory Lock

● 128 x 8-bit Internal RAM
● 15 Programmable I/O Lines
● Two 16-bit Timer/Counters
● Six Interrupt Sources
● Programmable Serial UART Channel
● Direct LED Drive Outputs
● On-chip Analog Comparator
● Low-power Idle and Power-down Modes
Component No. 9 and 13 Electrolytic Capacitor:An aluminum electrolytic capacitor, usually
simply called an electrolytic capacitor (e-cap), is acapacitor whose anode (+) consists of pure
aluminum foil with an etched surface, covered with a uniformly very thin barrier layer of
insulating aluminum oxide, which operates as a dielectric.
Component No. 10 Resistor: It is a passive two-terminal electrical component that implements
electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current
flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission
lines.
Component No. 11 LED: A light-emitting diode (LED) is a two-lead semiconductor light
source. It is a p–n junction diode, which emits light when activated.[4]When a suitable voltage is
applied to the leads, electrons are able to recombine with electron holes within the device,
releasing energy in the form of photons. This effect is called electroluminescence, and the color
of the light (corresponding to the energy of the photon) is determined by the energy band gap of
the semiconductor.
Component No. 12 Switch: It is a device for making and breaking the connection in an electric
circuit.
Component No. 14 7805 IC Voltage Regulator with Heat Sink: 7805 is a voltage
regulator integrated circuit. It is a member of 78xx series of fixed linear voltage regulator ICs.
The voltage source in a circuit may have fluctuations and would not give the fixed voltage
output. The voltage regulator IC maintains the output voltage at a constant value. The xx in
78xx indicates the fixed output voltage it is designed to provide. 7805 provides +5V regulated
power supply.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 38

 Door Interlock Control System

Chapter 5
CONCLUSION AND FUTURE SCOPE
5.1 Conclusion
Following are the tasks carried out during the internship at e-research center, Bangalore.
● Learned about the each electronic component, its working and interconnect them in the
general PCB.
● Writing the embedded C programs using Keil µ - version 3.
● Dumping the C programs on to the 8051 microcontroller development board by using
NUVOTON software.
● Using FLASH MAGIC software to check the serial communication output.
PCB schematic and layout designing on ORCAD10.5 software
5.2 Future scope
● In future we can add RFID or smart card to access.
● We can add figure print sensor or biometric sensor to give more authentication.
● Instead of push button we can use touch sensor.

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 39

 Door Interlock Control System

Dept of Electronics & Instrumentation Engg, Dr.AIT Page 40