【 Weak current College 】 weak electricity system design

Summary: the article from the current status of electronic design, analysis of the design work was unsatisfactory for several reasons, then focusing on articulate people a deeper understanding of the design, specification, and content to improve your design of the significance of the proposed design throughout the entire process of the project, the final detailed account-current design of several steps, each step of the work content and design of the General Department of coordination of Division.


Keywords: electronic system design of program steps needs content Division


1 Overview

In a sense, design is the success of the project, is a very important and challenging work, a good electronic design. However, the current domestic electronic design work also not optimistic, the reason I think the key is:
(1) of the subsystem more current system is believed to be involved in high-tech, an existing system, the specification is not very perfect, and some focus issues have not formed yet, successful and worthwhile experience in the construction of the chosen few, which is currently weak design difficult objective reasons.
(2) the lack of excellent designers and the quality of our designers to be improved is the man-made causes. Now some weak current designers often behind closed doors, serious reality and user needs, simply pursue a high standard, high scale, design characteristics and the same, no new ideas, many of these design project "inherent" power. Weak high-tech and complexity need designers (especially Chief Architect) with high-quality, he at least has a broad range of computers, communications, electric, water, warm, and other aspects of professional knowledge, you also need to have a rich design experience and skill and a keen on new technology forward.
(3) and other civil engineering, plumbing profession, weak current design in practical projects easily affected by other professional, unit personnel restraint that is professional in nature. Such as: design is often works late to be fully expanded, resulting in design time, considered too late; project bidding behavior, System product arbitrarily changed, causing many waste designing work; construction and decoration lags, user requirements of inappropriate, not explicit, so that the designer did a lot of wasted effort; user features subject to change at any time, to design a lot of inconvenience.
(4) people (including many owners, government authorities, some grade-a design Institute, large-scale construction units, supervision units, engineering company) on the entire electronic design mistakes, on the design of a program, process, content is not very clear, in the design of the "baton", designer-level differences between, design Division is also not reasonable.
Comprehensive analysis on, to make a weak current design features to improve the quality of the entire industry, in addition to the need to increase investment, actively promoting weak current professional theory in-depth study, through various means (especially the University Act) actively cultivate high-quality design talents both require a long-term effort, another very important, results in faster way is to change attitudes, putting the entire building program, publicity and specification, the current design of procedures, processes, content from chaos to understand, and to fully guarantee the consistency of design quality, will be able to change the current design of passive situation, like "no rules, no RADIUS", only to let everyone know and follow the rules and procedures, to make the design trend of normalization. So, a typical, perfect power design should include what steps and contents? I think should at least include the planning, design, conceptual design, detailed design (construction) as well as modify and expand design four most and weak current design work should permeate the entire process works.

2 planning and design

In order to make the design more rational, you must do before you design, planning and design is a very important but also very vulnerable to neglect of work, it includes: user needs analysis and planning (preliminary) design and feasibility study of the third step. User needs analysis: designers should first talk with owners oral, discussion and analysis of collecting user on the current system of the vision, requirements and issue qualified electronic system to achieve. On this basis, the designers of finishing the user the demand, the owners of quantitative requirements specification, that a scientific, strict, operational objectives, namely: from the features, performance, implementation, and costs combined with the existing products and related technologies to determine the target system.
Planning (preliminary): determination system objective basis, the designers should revolve around user needs and features of the building, from a macro perspective to the weak electricity system overall scale and performance indicators, various subsystems of the scale and performance indicators, the choice of technology and how to implement such as description and justification. The user system has an overall concept and understanding for future implementation and funding to do there, at the Centre and is the system of documents in the analysis phase. Planning typically include: the overall profile of the target system, the overall structure of the target system, a description of the subsystem. Including a description of the subsystem includes: System, system wiring structure, system implementation plan, system requirements. Planning to pay attention to the formation of illustrated and easy-to-understand language, design intent expressed in full for the relevant policy and technical staff as a demonstration and evaluation of the Foundation.
Feasibility study: introduced in planning, you should conduct a feasibility study, mainly on the necessity of building light current system, technological advancement, economic rationality of the judgment made clear, only the investigating judge in the course of the construction of the system, confirm that the above three, you can proceed to the next step in design.
The necessity of constructing 2.1
Many weak electronic systems with high performance, but it should be noted that not all cases can choose the system that should use the sector's actual situation, where the very necessary to install the system. In short, through investigation, the preliminary determination of different technology options, and then install contrasting through programmes that the weak electricity system has obvious advantages can only be implemented, andCan be used for some other equipment or methods, you do not install this subsystem.
2.2 economic rationality of the
Economic rationality has two meanings: one is the device selection and project investment costs reasonable; second, the system of input and output. That is, the construction of the subsystem,: from the economic benefit should be cost-effective, which means that the system itself, the sum of the depreciation expense and maintenance should be less than the use of this system to improve the efficiency of production (work), to improve the quality of the products (work), guaranteeing security and economic benefits achieved. Of course, here we are talking about benefit refers to the system itself creates benefits directly and indirectly created by the sum of the benefits. In short the installation system for scientific computation and analysis, determine its economic rationality is further implemented.
2.3 technology advancement
For a system of equipment selection, composition, and other design elements you want to pay attention to technical advancement. The so-called technical advancement is a design that meets user requirements and to meet national requirements specifications, but also has currently more advanced level, at least not able to use the product, which have been ongoing, but should not be blindly pursuing advanced, select the import device or introduced a complete set of system, consider the situation in our country, taking into account the user's skill level, future domestic equipment maintenance and parts source, in case the system placed in service after the repair work difficult.

3 overall design

Starting from the overall design, designers will be based on user requirements and the planning of the programme, taking account of the actual technical conditions, economic conditions and social conditions, determine the system's implementation. If, in the last stage, the designer's main task is to research, to understand the situation, then, from the stage of the main tasks in various technical means and implementing methods to cons, designed to maximize system reliability, availability and scalability. This is a class that derives from the target system to the specific implementation of progressive refinement of the design process, can be divided into two continuum and relatively independent stages: conceptual design and detailed design.
Overall design is on target systems and manpower and design, is a preliminary design modifications, additions and deepening, it includes: System design, integration, design, logic design, application design, coordinate the design, process design, environmental design, etc.



4 detailed design (engineering)

Engineering construction design is most important to system construction drawing design, it is the system design and construction of the floor plan design, usually in the system called the preliminary design and implementation of programmes designed to carry out the construction design.
Construction drawing design first, set the system initial design and construction programmes more principles of software and hardware configuration, system feature requires in-depth technical analysis and engineering calculation, precise technical data, and then draw on the plane in construction drawings. In particular, the integrated system needs more of some of its subsystems in the professional aspects of the installation process, interface, interface and detailed requirements and corresponding text description. Requirements for civil construction, reserved hole in embedded parts, wire and cable tray installation is required for the construction of the diagram has a clear position, size, orientation, etc, for system monitoring and management of all kinds of stereotypes and electrical equipment products of construction and installation diagram rendering should use the National Atlas to save common work and speed up the construction schedule.
Construction drawing design depth should meet the following requirements:
(1) civil construction required reserve hole, embedded parts and trunking, bridge of the positioning, size, and to the laying of the process and requirements.
(2) for electronic equipment room and weak current shaft power and grounding reserved, grounding can be combined with grounding, the resistance should not be greater than 1 Ω; the use of weak current separate earthing, grounding resistance should not be greater than 4 Ω.
(3) relatively unchanged layer (such as device layer), the dimensions of the part of the interval, building access network pipes embedded.
(4) central control room, the location of the weak current room size, layout requirements.
(5) the system locale controller (DDC), monitoring (IP/OP) positioning and installation requirements.
(6) the system wiring specifications and cabling requirements.
(7) system device number of the line termination.
Systems engineering construction drawings typically include: drawings directory, construction of General information, the weak electronic system system diagram, System pipeline plan, weak current shaft, room layout details, system wiring diagram with termination. Construction drawing design mainly to the drawings, if drawings that are not clear, but in general information, or the appropriate drawing supplemented with text, the text description is a supplement to the construction drawings. Due to the weak electricity system is centralized and unified integrated design, we design the construction plan is possible in a set construction plane drawings reflect subsystem on (in addition to the fire alarm system according to the specification to be subject to independent design) of preformed line pipe and cable tray installation of an assembly line and the wiring, and the corresponding equipment positioning.

5 modify, expand and perfect design

Modify Design: in the current system of construction and installation, after the system, the subsystems with discussion and system features, indicators, if you find features, performance indicators for non-compliance or irregularities, only by modifying the design to meet the system requirements of your applications. Expanded sound design: building weak electricity projects from initiation through design, construction, installation, testing, assessment and acceptance of approximately 2-3 years, a long build cycle, due to technical developments and to deepen understanding of the system, system acceptance will make the system has a lot of imperfections, need to expand the design. Expansion of design content depends entirely on the needs of users, the expansion of design work done, often played the role of the icing on the cake.
From system planning for the design of complete systems expand, the entire building intelligent systems engineering completed a design cycle. In the design cycle, design departments and staff do not usuallyIs immutable. Domestic currently able to bear the weak design sector part category: Design Institute from the 1980 's, in a competitive, constantly changing public functionaries and followed in the past by Soviet design system of the old, the commodity economy and Europe's impact on design and construction system, the reform is to accelerate progress, to keep up with the big building great pace, but most of the Design Institute in mastering and using the latest technology in the world, business management, design engineering experience of apparent defects, etc. The System Integrator is the rise of the 80 's, a service provider that he does not directly engage in hardware and software production and development, and is active in between users and manufacturers, according to the needs of the design system-building programmes, to choose between different manufacturers combination to their skills and experience for the user to build a suitable system, and to bear on the user's training and tracking service. Involves a large number of high technology and industrial power design, wish to let the Design Institute "package and conquer the world" is not possible. Steps from the design, content and Design Institute and system integrators the ability and work direction, planning, design and overall design consists of a strength of the category Design Institute, detailed design and system modifications to expand design by system integrators, is a more sensible division of labour. The Institute's primary responsibility is to complete the overall scheme and system design, and solve and other professional equipment and construction of the pipeline. System integrators, under the direction of the Institute to carry out a detailed, modify, expand and perfect design.