Tuesday, 20 November 2012

File Checksums

A checksum (also known as hash sum) is a fixed size value which is computed from an arbitrary block of digital data for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. It basically allows us to check the validity of something. Usually, checksums are used in data transmission contexts to detect if the data has been transmitted successfully. The integrity of the data can be checked at any time later on, by recomputing the checksum and comparing it with the stored one. If the checksums do not match, the data was certainly altered, either intentionally or unintentionally.

Monday, 19 November 2012

RSView32 Active Display System


It is a true client/server application that adds on to and extends the reach of our RSView32 HMI software. By means of RSView32 Active Display System, we can view and control our RSView32 projects from remote locations.

RSView32 Web Server

It allows anyone with a valid RSView32 user account to access snapshot views of graphic displays, tags, and alarms through any standard web browser.

Add-on Architecture

Add-on architecture (AOA) technology expands RSView32's functionality by integrating new software components directly into RSView32. We can customize RSView32's feature set by installing only those components which we require. RSView32 includes the following AOA components that we can install separately at no extra cost:
  • RSView32 Messenger: It provides powerful alarm annunciation, paging, and messaging tools.
  • RSView32 TrendX: It monitors real-time data and provides historical trending from RSView32 data logs.
  • RSView32 SPC: It offers integrated & real-time Statistical Process Control.
  • RSView32 RecipePro: It enhances RSView32 recipe management and control.
  • RSLadder: It displays ladder logic for the Allen-Bradley SLC 500 and PLC-5 families of processors. 

Thursday, 15 November 2012

RSLogix 5 Benefits 1



Following are the major benefits offered by RSLogix 5:

Ladder

Via RSLogix 5 all project information can be consolidated and displayed as a Project Tree with "Point-and-Click" accessibility. Numerous rungs are edited simultaneously and program using symbols that we have not yet assigned addresses to using the Program Editor. Besides, errors get corrected at our own convenience using the Project Verifier.

Cross-Reference Information

RSLogix 5 enables us to move to any rung or instruction we require by clicking on the cross-referenced item using the Online Cross-Reference. Cross-reference information can be viewed simultaneously with our control program online or on a report.

Drag-and-Drop Editing

By means of RSLogix 5 one can:
  1. Add addresses to instructions by dragging them from the Data Table Monitor, Database Files, or the Address/Symbols Picker to the desired instruction.
  2. Rapidly move instructions within a project or from one project to another.
  3. Move data table elements from one data file to another. 

Monday, 12 November 2012

Absorptance

Absorptance also referred to as absorption factor is the property of a body which determines the fraction of the incident radiation or sound flux absorbed or absorbable by the body. It is defined as the ratio of the luminous or radiant flux absorbed by a body to the flux falling on it. It is usually represented by the Greek letter α (alpha). It was previously known as absorptivity. In the case of a blackbody, absorptance i.e. α = 1. Standard unit of absorptance is percent (%) or a factor between 0 and 1.

Friday, 9 November 2012

Compact Fluorescent Lamps - Advantages & Disadvantages


 Advantages

Compact fluorescents offer following advantages over incandescent light bulbs:
  • Lower power consumption i.e. CFL consumes 1/4 the energy, and produce 90% less heat as compared to incandescent lamps.
  • Longer lifetime (last up to 10 times longer than incandescent lights)
  • Produce more light

Disadvantages

  • Longer starts
  • More expensive than incandescent lamps owing to their higher initial cost.
  • CFLs are physically larger than incandescent lamps which may make them difficult to use in some light fixtures.
  • Fluorescent tubes contain a microscopic amount of mercury. It is such a small amount that disposal is not generally regulated as with full size fluorescents. Hence we should use caution to avoid crushing the tubes, and dispose of them safely. 

Thursday, 8 November 2012

Compact fluorescent lamp

Compact fluorescent lamps are smaller versions of standard fluorescent lamps. They consume between 5 to 27 watts, and have a brightness and color interpretation that is equivalent to incandescent lights. Unlike standard fluorescents, they can directly replace standard incandescent bulbs. Compact fluorescent lamps (CFLs) combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures.

Working of CFL

Compact fluorescent lamps work to a great extent like standard fluorescent lamps. They consist of two parts:
  1. A gas-filled tube
  2. Magnetic or Electronic ballast
The gas in the tube glows with ultraviolet light when electricity from the ballast flows through it. This in turn excites a white phosphor coating on the inside of the tube, which emits visible light throughout the surface of the tube. Compact fluorescent lamps with magnetic ballasts flicker slightly when they start. Besides, they are heavier than electronic ballasts. Electronic ballasts are more expensive than magnetic ballasts. However, they are more efficient especially at low temperatures. Most currently available CFLs have electronic ballasts.

Compact Fluorescent Lamp Main Features

by Chipkin Automation Systems

Tuesday, 6 November 2012

Halogen Cycle


Halogen lamp is filled with the same inert gases as incandescent lamps mixed with small amounts of a halogen gas (generally less than 1% bromine). The halogen chemically reacts with the tungsten deposit to produce tungsten halides. When the tungsten halide reaches the filament, the intense heat of the filament causes the halide to break down, releasing tungsten back to the filament. This process is known as the tungsten-halogen cycle and it maintains a constant light output over the life of the lamp. To make this halogen cycle to work following are the basic requirements:
  • The bulb surface must be very hot otherwise the halogen may not effectively vaporize or fail to adequately react with condensed tungsten.
  • The bulb needs to be smaller and made of either quartz or a high-strength, heat-resistant grade of glass known as aluminosilicate.
Since the bulb is small and reasonably strong due to its thicker walls, it can be filled with gas to a higher than normal pressure. This slows down the evaporation of the tungsten from the filament, increasing the life of the lamp. The higher pressure and better fill gases can extend the life of the bulb and permit a higher filament temperature which results in better efficiency.