Saturday, November 22, 2008

Definitions Of Programmable Logic Controller (PLC)

Programmable Logic ControllersProgrammable Logic Controllers (PLC) is a computer that is easy to use electronic or user-friendly control functions that have for various types and levels of difficulty diverse. Definition Programmable Logic Controller is electronic systems that operate digital and designed for use in the environmental industry, which uses a memory system that can be programmed for storage in the internal instructions that implement specific functions such as logic, sequence, time, counter and operating aritmatik to control the engine or through the process modules I / O digital and analog.

Based on the concept of PLC name is as follows:

Show ability in terms of memory to store programs that have been made that easily changed the function or usefulness.

Shows the ability to process the input in the aritmatik and Logic (ALU), which is conducting operations compare, enumerate, multiply, divide, reduce, inverter, AND, OR, and others.

Shows the ability to control and manage processes that produce the desired output

PLC is designed to replace a series of relay sequensial in a control system. In addition can be programmed, the tool can also be managed and operated by people who do not have the knowledge in the field of operation of the computer specifically. PLC has a programming language that is easily understood and can be operated when the program was created by using the software in accordance with the type of PLC used is entered.

This instrument works based on inputs that are depending on the circumstances and at a certain time then that will or ON-OFF-I output-output. '1' shows that the situation is expected to be met while the '0' situation is not expected to be met. PLC can also be applied to the control system that has a lot of output.

PLC Functions

A. In general
PLC function and usefulness in practice PLC can be divided in general and specifically. PLC functions are as follows:

Control sequence
PLC to process the input signal into a binary output that is used for the purpose of processing techniques sequentially, in order to maintain the PLC step in the right sequence of the process.

Monitoring Plant
PLC continually monitors the status of a system (such as temperature, pressure, high altitude) and take the necessary action in connection with a controlled process (for example, the value has exceeded the limit) or display a message on the service.

B. Special functions
PLC to provide input to the CNC (Computerized Numerical Control). Some PLC can provide input to the CNC to the interests of further processing. CNC when compared with the PLC has a higher accuracy and more expensive. CNC is usually used for the finishing process, establish working object, technology molding and so forth.

CNCThe working principles of a PLC is to receive input signals a process manageable, then do a series of instructions to the logic input signals in accordance with a program stored in memory and generate output signals to control the Actuator or other equipment.

Voice Over Internet Protocol

VoIPVoice over Internet Protocol (VoIP), or with other Internet names Telephony is associated with the transmission of voice, is a technology for transmission of data including the usual form of data, voice or video in real time through the Internet (IP channel). In the transmission of voice applications, VoIP is strong candidate to replace the conventional phone network using the PBX (private branch exchange). This is because the cost is cheaper, especially for long-distance connection. Moreover, now said that the quality of the VoIP service can exceed the quality of network services conventional. In the process adoption, various obstacles appear, especially for telecommunications technology company in such a way so that difficult to 'upgrade ' networks.

VoIP Interfaces

VoIP using standard ITU (International Telecommunication Union) H.323 standard for communication. H.323 standard consists of components, protocol, and procedures that provide multimedia communication via packet-based network. The form of packet-based network that can be passed between other Internet network, Internet Packet Exchange (IPX)-based, Local Area Network (LAN) and Wide Area Network (WAN). H.323 can be used for multimedia services such as voice communication (IP telephony), video with voice communication (video telephony), and combined voice, video and data.

Design and development goal is to enable H.323 interoperability with other types of multimedia terminals. With a standard terminal H.323 can communicate with H.320 terminals on the N-ISDN, H.321 terminals on the ATM, and H.324 terminal switched on the Public Telephone Network (PSTN). Terminal H.323 real-time communication allows two-way form of voice, video and data. H.323 standard consists of 4 components of physical I used when connecting communication multimedia point-to-point and point-to-multipoint on some kind of network:

VoIP NetworksTerminal
multimedia communications for the real-time two-way. Terminal H.323 can be a personal computer (PC) or other means of self that can run multimedia applications.

Used to connect two different networks, namely between H.323 network and a network of non H.323, for example, the gateway can connect and provide communication between the terminals with H.233 phone network, for example: PSTN. In the form of a network connecting the two different done with the protocols for call setup and release and send information between networks connected to the gateway. However gateway is not needed for communication between the two terminals of H.323.

Can be considered as a brain on the network because H.323 is a point important in the H.323 network.

Used to service the terminal H.323 conference three or more. All terminal who want to participate in the conference can build relationships MCU with the materials for the conference, negotiations between terminals to ensure the audio or video coder / decoder (codec). According to the H.32 standard, a MCU consists of a Multipoint Controller (MC) and several Multipoint Processor (MP). MC Negotiations handle H.245 (concerning signaling) between the terminals to determine the ability audio and video processing. MC also to control and determine the series audio and video will be multicast. MC does not face directly the media. This task was given to the MPs who make Mix, switches, and process audio, video, or bits - bits of data. Gatekeeper, gateway, MCU and the logic is a separate component in the standard H.323 but it can be implemented as a means of a physical.

How To Access The VoIP

VoIP adapterTo access the necessary VoIP Terminal Adapter or SoftPhone. SoftPhone is a software-based VoIP terminals such as Netmeeting. For it is necessary Soundcard computer equipped with a headphone and microphone following. Connection to The Internet can use a dial-up modem or xDSL. theoretically modem 14.4 kbps is sufficient for the learner-VoIP.

However, DSL Flatrate better for VoIP. Neither because the higher the speed, but the connections of 24 hours. So that VoIP normal telephone functions such as: contact and can be contacted at any time. To This actually needs more appropriate when used TA (Terminal Adapter).

TA is a from of the small aircraft that can be connected to a VoIP network without using the computer. So the computer does not have to light only for 24 hours standby waiting for incoming phone calls. In addition to electricity also noisy. You can connecting ordinary telephones (including wireless telephones) to the TA, so that you there is no need to use headphones or a microphone. With VoIP TA really feels like a normal telephone.

Sunday, November 16, 2008

Offshore Communication With WiMAX

WiMAX network low-cost than the network such as 3G. Oil and gas producers can use WiMAX equipment to provide communication links from land-based facilities to oilrigs and platforms, much to support operations, security, and basic communication and easy for the degree. Monitoring remote monitoring of the site, and access databases. For example, a video clip from one component or subassemblies can be sent to land-based team of experts for analysis. Including the security alarm monitoring and supervision of the video. Basics include voice communication telephony, email, Internet access and video conferencing. The network can be set or redeployed in a matter of hours, minutes, if not, even when oilrigs and platforms that moved to another location.

Offshore Wimax
Cable solutions are not appropriate for this scenario, because the facilities offshore, and since oilrigs are moved regularly and are in the field of oil or gas. Communication to monitor the status of the assets can be maintained, using battery-supported WiMAX terminals. Communication with WiMAX networks have a large bandwidth and multiple modulation used in accordance with the distance including BPSK,QPSK,16-QAM and 64-QAM. When equipped with a high-power amplifier and operating with a low-level modulation namely BPSK or QPSK.