A SCADA System Assessment

Written by Randy Dennison

A Pre-SCADA System Assessment

By Randy Dennison

Introduction Supervisory Control and Data Acquisition (SCADA) is a process control system that enables a site operator to monitor and control processes distributed among various remote sites. Such systems can be used to monitor and control land, air or water pollution control equipment, or just about any manufacturing process.

A properly designed SCADA system saves time and money by eliminatingrepparttar need for service personnel to visit each site for inspection, data collection/logging or make adjustments. Real-time monitoring, system modifications, troubleshooting, increased equipment life and automatic report generating are just a few ofrepparttar 110095 benefits that come with today’s SCADA systems.

As technology continues to advance, such systems will berepparttar 110096 operating standard for process control. But from hundreds of system providers available today, which one will a facility choose to partner with and why?

Choosing a system provider that will design a system applicable to an operator’s needs can be an overwhelming, confusing task. With little or no knowledge of SCADA and telemetry systems and an incomplete pre-system assessment, decisions can include costly mistakes. Too oftenrepparttar 110097 decisions are based upon:

Price: The quality of system components and workmanship may suffer when vendors low-bid to winrepparttar 110098 contract. The vendor may then indiscriminately cut costs to make a profit. Proprietary equipment – If proprietary, closed-protocol equipment is installed inrepparttar 110099 system,repparttar 110100 customer can be forced to pay inflated prices and facerepparttar 110101 possibility of future equipment integration problems due to obsolete or irreplaceable components, company shutdowns and a lack of support when it comes time for repair.

Excessively complex or customized equipment: Ifrepparttar 110102 SCADA system is too complex to understand, operate and support,repparttar 110103 only recourse is to purchase expensive training and/or service contracts, which do not always guarantee prompt and professional service.

Years of experience or knowledgeable expertise: There are a host of reputable SCADA providers, with years of experience and knowledgeable expertise, who have designed systems that are too broad or expensive. Experience and knowledge are important but only as a starting point when selecting a vendor.

Sales people and/or flashy marketing: Effective sales and marketing strategies are meant to produce top-of-mind results. Avoid being lured or pressured into a purchase. Be equipped and make a sound decision based on all factors that affect optimum system performance.

These and other costly mistakes can be avoided through knowledge, understanding and careful assessment. Some will only need to consider Tables A and B of this article. Others, with little or no SCADA knowledge, will need to familiarize themselves with more background information.

A Brief History SCADA began inrepparttar 110104 early 1960s as an electronic system operating as input/output transmissions between a master station and a remote station. The master station would receive data through a telemetry network and then storerepparttar 110105 data on mainframe computers.

Inrepparttar 110106 early 1970s, distributed control systems (DCS) were developed to control separate remote subsystems and inrepparttar 110107 1980s, withrepparttar 110108 development ofrepparttar 110109 microcomputer, process control could be distributed among remote sites. Further development enabled DCS to use programmable logic controllers (PLC), which haverepparttar 110110 ability to control sites without taking direction from a master.

Inrepparttar 110111 late 1990s, SCADA systems were built with DCS capabilities and systems were customized based on certain proprietary control features built in byrepparttar 110112 designer. Now, withrepparttar 110113 Internet being utilized more as a communication tool, SCADA and telemetry systems are using automated software with certain portals to download information or control a process.

Engineered SCADA systems today not only control processes but are also used for measuring, forecasting, billing, analyzing and planning. Today’s SCADA system must meet a whole new level of control automation while interfacing with yesterday’s obsolete equipment yet remain flexible enough to adapt to tomorrow’s developments.

Whetherrepparttar 110114 requirement is a new system or upgrading an older one, it is important to knowrepparttar 110115 system components before deciding on who to talk with and what equipment is needed for a particular application.

System Components The four major SCADA system components includerepparttar 110116 Master Terminal Unit (MTU),repparttar 110117 Remote Terminal Unit (RTU), communication equipment and SCADA software.

The MTU is located atrepparttar 110118 operator’s central control facility and provides a man-machine software interface, two-way data communication and monitoring/control of remote field devices.

The RTU, located at a remote site, gathers data from field devices (pumps, valves, alarms, etc.) into memory untilrepparttar 110119 MTU initiates a send command. The central processing unit withinrepparttar 110120 RTU receives a data stream via hardware equipment protocol. Whenrepparttar 110121 RTU sees its specific address embedded inrepparttar 110122 protocol, data is interpreted andrepparttar 110123 CPU directsrepparttar 110124 specified action to take. The protocol used can be open like Modbus, TCP/IP or a proprietary closed protocol. Some RTUs, called “smart PLCs” or remote access PLCs, provide remote programmable functionality while retainingrepparttar 110125 communications capability of an RTU. These devices are designed to perform control functions, check site conditions, re-program anytime from anywhere, and have any alarm or event trigger a call to a personal computer without any direction fromrepparttar 110126 MTU.

The wayrepparttar 110127 MTU/RTU transmission network or topology is set up can vary, butrepparttar 110128 system must feature uninterrupted, bi-directional communication in order to properly function. Methods to accomplish this include private medium, whererepparttar 110129 end user owns, operates, licenses and servicesrepparttar 110130 medium, and/or public medium, whererepparttar 110131 customer pays for a monthly, per time or volume use.

Can bamboo flooring really help save the worlds’ environment?

Written by S.A. Smith

Probably not on its own, but its an excellent example of how consumers can vote with their buying dollars to sway market demand to bring more environmentally friendly products intorepparttar marketplace.

Bamboo flooring is a rising trend in home flooring and a great alternative to traditional hardwood floors. It isrepparttar 110094 most environmentally friendly natural hardwood flooring alternative you can select for your home, it is a renewable resource, is stronger than steel, and has a greater resistance to expansion and contraction problems associated with temperature and humidity changes.

The bamboo grass is one ofrepparttar 110095 fasted growing plants onrepparttar 110096 planet, only takes 5 years to grow to maturity, and can provide 25 timesrepparttar 110097 bio mass of a comparable stand of trees. Bamboo is harvested every 5 years, and starts to re-grow immediately with new shoots when harvested. Bamboo is also strong and has a tensile strength exceeding mild steel. It can withstand up to 50,000 pounds of pressure per square inch versus some steels 50,000 psi ratings.

Bamboo flooring is also become a very trendy interior design statement with its rich and beautiful golden earth tones. It is important to shop around for a quality bamboo flooring product that contains no formaldehydes in its binding compounds. Many offshore brands use cheaper binding agents that may contain formaldehydes, and this can cause indoor air pollution problems downrepparttar 110098 road as all chemical compounds will slowly release their toxins intorepparttar 110099 air.

Cont'd on page 2 ==>
ImproveHomeLife.com © 2005
Terms of Use