Question

Draw a block diagram to show the communication process between a transmitter and a receiver. By referring to the diagram you draw, explain the role of ELV systems in enhancing the communication effectiveness and efficiency.

Answer 1

Ans:

The elements of basic communication system are as follows

• Information or input signal
• Input Transducer
• Transmitter
• Communication channel or medium
• Noise
• Receiver
• Output Transducer

Fig:Block diagram of Communication system

1. Information or input signal

• The communication systems have been developed for communicating useful information from one place to other

• The information can be in the form of sound signal like speech or music or it can be in the form of pictures.

2. Input Transducer

• The information in the form of sound, picture or data signals cannot the transmitted as it is.

• First it has to be converted into a suitable electrical signal.

• The input transducers commonly used in the communication systems are microphones, TV etc.

3. Transmitter

• The function of the transmitter block is to convert the electrical equivalent of the information to a suitable form

• It increases the power level of the signal. The power level should be increased in order to cover a large range. The transmitter consists of the electronics circuits such as amplifier, mixer, oscillator, and power amplifier.

4. Communication channel or medium

• The communication channel is the medium used for the transmission of electronic signals from one place to the another.

• The communication medium can be conducting wires, cables, optical fibres or free space. Depending upon the type of the communication medium, two types of the communication system will exist

  a. Wire communication or line communication

  b. Wireless communication or radio communication

5. Noise

• Noise is an unwanted electrical signal which gets added to the transmitted signal when it is travelling towards receiver.
• Due to noise, the quality of the transmitted information will degrade. One added the noise cannot be separated out from the information
• Hence noise is ab big problem in the communication systems.

6. Receiver

• The reception is exactly the opposite process of transmission. The received signal is amplified and demodulated and converted in a suitable form

• The receiver consists of the electronic circuits like mixer, oscillator, detector and amplifier.

7. Output Transducer

• It consists of the electrical signal at the output of the receiver back to the original form i.e. sound or TV pictures.

• The typical example of the output transducers are loud speakers, picture tubes etc.

ELV(Extra Low Voltage)

Smart Buildings are becoming more and more popular as they reduce energy costs, enhance productivity and building operations and support sustainability efforts.

ELV systems are becoming a necessity for smart buildings to make building infrastructure more intelligent, interconnected and efficient. They are used for security, communication, lighting, air-conditioning and heating. It includes systems such as fire detection and alarms, voice evacuation, voice and data communications, public address, access controls, intrusion detection, CCTV, audio-visual, cell phone and wireless distribution, plus other such auxiliary systems.

Traditionally, ELV systems are supplied by various OEMS under different contracts: HVAC controls with mechanical services; access control and lighting in electrical services, etc., which run on proprietary networks as well separate telephone, data and television networks. To operate and run these systems, OEMs provide their own workstations along with software application. Each system has its own control system which communicates over different communication protocols.

The integration of these multiple sub-systems on a common network platform is therefore, becoming essential. The ELV systems integration approach supports the installation of common cabling and pathways instead of individual systems, thus resulting in improved total system monitoring and management, and significant cost reductions.

It requires in-depth knowledge of technologies and a strong team of domain experts who design, integrate and deliver Integrated ELV Systems that meet diverse needs.

Information technology has a key role to play in the development and operations of dynamic Smart Buildings. For example, a Smart Building HVAC system can automatically precool a building or regulate temperature based on number of occupants inside the building or outside temperature. Based on operational conditions, the system will take corrective actions which lead to reduced energy demand / consumption. Further information can be shared with the electricity grid to support grid reliability through demand response.

The major features of an IELVS design are:

• Modern ELV System runs on IP based communication which reduces investment in cables and cables trays (pathways).
• Reduces major efforts required during design and installation which cause unexpected delays on project time lines.
• Open architecture uses open communication protocol, standards and specifications which avoids dependency on single vendor.
• Expansion, upgrades and installation of news systems becomes easy and can be sourced from different suppliers.
• Integrated ELV solutions are considerably easier to troubleshoot in case of failure as it involves minimal cabling and interconnection.
• These systems can be operated remotely as well as managed and reconfigured which saves maintenance costs.
• It offers additional features and functionalities compared to traditional ELV Systems.

In conclusion, rapid deployment of cost-effective ELV Systems, integration of IT, building automation and controls are playing a significant role in the facilities management industry. Asset owners are realising the importance of Integrated ELV systems which are scalable, secure and open platforms that offer cost savings and enable energy savings as well as sustainable improvements.