mardi 2 décembre 2014

Difference Between DCS and SCADA


DCS vs. SCADA
DCS and SCADA are monitoring and control
mechanisms that are used in industrial installations
to keep track and control of the processes and
equipment; to ensure that everything goes smoothly,
and none of the equipment work outside the
specified limits. The most significant difference
between the two is their general design. DCS, or
Data Control System, is process oriented, as it
focuses more on the processes in each step of the
operation. SCADA, or Supervisory Control and Data
Acquisition, focuses more on the acquisition and
collation of data for reference of the personnel who
are charged with keeping track of the operation.
DCS is process state driven, while SCADA is even
driven. DCS does all its tasks in a sequential
manner, and events are not recorded until it is
scanned by the station. In contrast, SCADA is event
driven. It does not call scans on a regular basis, but
waits for an event or for a change in value in one
component to trigger certain actions. SCADA is a bit
more advantageous in this aspect, as it lightens the
load of the host. Changes are also recorded much
earlier, as an event is logged as soon as a value
changes state.
In terms of applications, DCS is the system of choice
for installations that are limited to a small locale,
like a single factory or plant, while SCADA is
preferred when the entire system is spread across a
much larger geographic location, examples of which
would be oil wells spread out in a large field. Part of
the reason for this is the fact that DCS needs to be
always connected to the I/O of the system, while
SCADA is expected to perform even when field
communications fail for some time. SCADA does this
by keeping a record of all current values, so that
even if the base station is unable to extract new
information from a remote location, it would still be
able to present the last recorded values.
Summary:
1. DCS is process oriented, while SCADA is data
acquisition oriented.
2. DCS is process state driven, while SCADA is event
driven.
3. DCS is commonly used to handle operations on a
single locale, while SCADA is preferred for
applications that are spread over a wide geographic
location.
4. DCS operator stations are always connected to its
I/O, while SCADA is expected to operate despite
failure of field communications....s.velmurugan

samedi 14 juillet 2012

heat pumps

  










    The term industrial equipment covers a very wide range of devices. These can include everything from ball bearings and air tools to large bulldozers, cranes, cement mixers and backhoes and just about everything in between such as compressors, check valves, couplings, dollies and dust collectors. Basically, just about any type of device that is used in the industrial world could be considered to be industrial equipment. Some types of industrial equipment are operated by manual labor while others are power-generated.

    All types of tools and equipment devices have been developed and used by man since prehistoric times however the first forms of modern industrial equipment were born along with the Industrial Revolution, which took place in Europe during the 18th and 19th centuries. This major technological and cultural change introduced the world to machinery, which was created to replace and help make manual labor easier. Steam power and powered machinery was suddenly developed for the manufacturing world and with it came the first industrial metal machine tools and industrial equipment.
As the industrial world began to grow new types of equipment and machinery were developed. These tools and equipment were designed to be powered by human and animal power along with such things as electrical, solar, nuclear and water energy. Some devices are operated manually while others such as robotics can be programmed to perform their functions automatically. Some types of equipment such as levers and hammers are simple tools while others such as hydraulic motors are pieces of complex machinery.
While many articles of industrial equipment such as ladders, power tools, hand tools, heaters, generators, and compressors can be used around your home, office, cottage and garden, some devices are built to a much larger scale and are made specifically for use in industrial settings. Some of these articles include industrial heaters, industrial carts, industrial forklifts, industrial vacuum cleaners, industrial presses, industrial boilers, industrial ovens, industrial furnaces and industrial scales etc. However, no matter where you use them, the one thing that all articles of industrial equipment have in common is that they were built and designed to make manual labor become faster and easier.