About of DIRECT DIGITAL CONTROL
Digital controls for HVAC, building automation, lighting control, energy management, and OPC solutions
Search the web Search this site ASI Controls manufactures Direct Digital Controls (DDC) for the Heating, Ventilating, and Air Conditioning (HVAC) and light industrial marketplace.. We offer a powerful, cost-effective, and easy to configure family of web enabled, OPC compatible, controllers, peripherals and software products.. Our network of delivers complete solutions for Energy Management, Building Automation, Green Building and other requirements for facility control.. Customers value our reliability, unparalleled flexibility in configuration, price performance, strong customer support, and extensive interoperability with OPC enabled controls from other manufacturers.. See ASI Controls intuitive configuration interface and learn more about capabilities and features.... ASI Controls reseller solutions include complete Energy Management Systems in large commercial buildings, HVAC and lighting control systems for design-build projects, Building Automation Systems, integrated facility management for retail networks, pre-programmed controllers for packaged devices in a single zone, specialty telecommunications panels, and more.
Analog Devices: Analog Dialogue: Single-Chip Direct Digital Synthesis vs. the Analog PLL
. A major advantage of a DDS system is that its output frequency and phase can be precisely and rapidly manipulated under digital processor control.. Other inherent DDS attributes include the ability to tune with extremely fine frequency- and phase resolution (frequency control in the millihertz (mHz) range and phase control < 0.09°, and to rapidly "hop" in frequency (up to 23 million output frequency changes per second).. A simple digital instruction set for control minimizes the complexity of support hardware.. They require only a data clock and data/address bus to control the output frequency and phase and to enable the sleep mode.. The combination of fast output hopping, digital control, low output distortion, and high tuning resolution makes the Complete-DDS solution a viable alternative to analog PLL synthesizers.
ADI - Analog Dialogue | Direct Digital Synthesis (DDS)
. Why would one use a direct digital synthesizer (DDS)? Arent there other methods for easily generating frequencies? The ability to accurately produce and control waveforms of various frequencies and profiles has become a key requirement common to a number of industries.. Can multiple DDS devices be synchronized for, say, I-Q capability? It is possible to use two single DDS devices that operate on the same master clock to output two signals whose phase relationship can then be directly controlled.
Direct-Digital-Control Procurement Options
Published July 2003, HPAC Engineering Direct-Digital-Control Procurement Options The advantages and disadvantages of eight approaches By J.. Article sections: In a perfect world, we would be able to buy devices from different controls manufacturers and have them work flawlessly on a user-friendly intuitive-programming and graphical-user-interface (GUI) platform.. For example, we would be able to plug any variable-air-volume (VAV) controller into our control network and get a pop-up screen confirming the connection and asking us if we would like to download the latest driver.. This article discusses the pros and cons of eight approaches to procuring direct-digital-control (DDC) systems: Open bidding.. Sole-sourcing with price controls.. The owner as controls installer.. Open-bid procurement may be an excellent choice for a building where no expansion is planned, and all necessary control points are procured initially.. A few to more than a dozen control vendors generally can meet the needs of a given project.
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Fundamentals of Direct Digital Control
Published May 1996, HPAC Engineering Fundamentals of Direct Digital Control The basic components and functions common to most DDC systems for commercial building HVAC control By ALEX J.. (Any extra are superfluous and likely wrong--my words.) In this article we will use Occam's Razor to carve away the excess rhetoric and verbiage surrounding direct digital control (DDC).. This article will examine the basic components and functions common to most DDC systems for commercial building HVAC control, from the point of view of specifier, owner, and operator.. While automatic control devices have been in use for a long time, in the past the many logical functions that were required to make the decision on if, when, and by how much to move a valve or damper were combined in one or two electro-mechanical devices.. The fundamental difference between past control devices and DDC is that the logic is separated from the device.. This is tremendously liberating for building designers and operators as the control sequences are now limited only by their knowledge and imagination.
AutomatedBuildings.com Article - Direct Digital Controls
AutomatedBuildings.com Article - January 2003 Delta Controls (Click Message to Learn More) I believe the possibilities of this type of technology for the future is unlimited.. From the space shuttle to the refrigerator in our homes, almost every mechanical device we can think of requires some type of control, and in most all cases it will be Direct Digital Control.. Des Rosiers Occupational Studies, 3881 Section 002 May 1, 2001 Course Paper INTRODUCTION AND THESIS STATEMENT The objective of this paper is to introduce a fairly new technology that has been developing and improving over the past forty years in environmental quality controls; the control of air conditioning systems with Direct Digital Controls.. The control of air-conditioning systems today are critical due to the high cost of energy, and the requirements made by science and industry.. Air quality control systems have come a long way in the past forty years.. Beginning with electric controls, then pneumatic controls, electronic controls, and today we have "Direct Digital Controls." This paper will present a better understanding of Direct Digital Controls, and the improvements made over all prior systems of air quality control.
It's time for direct digital control Engineered Systems - FindArticles
IN > > > > Article Content provided in partnership with FIND IN Find Magazines by Topic It's time for direct digital control , by So you're doing the usual packing for a business trip.. Sure, we'll always give you the magazine the old-fashioned way, but believe me, the electronic options and easy signup make this the Fastest and cheapest digital control retrofit you will ever encounter.
Jesper's AVR pages - MiniDDS
. It's controlled over RS232 from a small Windows program, and can generate Sine-, Sawtooth-, Trangle- and Sqare-waves ranging from 0.07 Hz to about 200-300 kHz in 0.07 Hz steps ( depending on your crystal ).. Windows Control program I wont go into details about how a DDS synth works.. The MAX603 handles the voltage regulation as well as the powerup/shutdown function, and is controlled by the DTR signal on the serial interface.. So when you shut down the control program on the PC, the miniDDS will be shutdown, saving battery.
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ASHRAE Offers Course on Direct Digital Control Retrofi Search Shortcuts Member Login Number: PIN: Quick Links ASHRAE Offers Course on Direct Digital Control Retrofits Courses Previewed at 2004 AHR Expo Release Date: 08/21/2003 Contact: Phone: 404-636-8400 ATLANTA -- Details on how to successfully plan and implement a direct digital control (DDC) retrofit of an existing control system will be presented in a new professional development seminar from ASHRAE.. Direct Digital Control Retrofit: From Project Planning Through Performance Verification is one of four new ASHRAE Learning Institute courses that will be available at ASHRAE's 2004 Winter Meeting, Jan.. It addresses an array of issues, such as determining the scope of the retrofit, when to use open protocols, how to evaluate contractor bids, keys to successful DDC specifications and a unique process for performance verification of the installed control system.. The course includes numerous examples, including energy efficient sequences, detailed points list and analysis of monitored data to troubleshoot the control system.
Direct Digital Control - What does DDC stand for? Acronyms and abbreviations by the Free Online Dictionary.
. TheFreeDictionary Google Word / Article Starts with Ends with Text subscription: Acronyms DDC(redirected from Direct Digital Control ) 0.01 sec.
Direct Digital Control (DDC) Advantages
Direct Digital Control (DDC) Advantages Energy Efficiency and DDC Advantages DDC EMCSs replace conventional pneumatic or electromechanical HVAC control systems with equipment capable of performing not only control but energy management and system diagnostic functions in the environment of a centralized computer network.. An EMCS accepts analog, discrete, and digital input from remote sensors and devices, processes the data, and then controls remote mechanical equipment.. An EMCS inherently has more accurate control because it reduces the drift, maintenance and recalibration problems common with pneumatic control systems.. Quality control, production, research, and maintenance will all benefit from the increased information flow when it is properly managed.. Compared to conventional control systems, DDC offers the following advantages: · Control Precision, · , · , · , · Retrofit Identification, · System Load Tracking, · , · Trend Information and History data, and · .
Direct Digital Control as part of B2B Service of the innovations-report
Forum for Science, Industry and Business Sponsored by: Search our Site: Topic (optional): Companies offering "Direct Digital Control" Product / Service Company / Organisation 2 Entries for "Direct Digital Control": Brauns Control GmbH (D) Saia-Burgess GmbH & Co.
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HVAC-Talk: Heating, Air & Refrigeration Discussion - Direct Digital Control - A Short Primer by Norm Christopherson
> Direct Digital Control - A Short Primer by Norm Christopherson Author Thread BC1 Professional Member Registered: Sep 2004 Posts: 173 Digital controls have been with us for years, yet those of us who do not regularly work with them are not always aware of their full capabilities.. Direct digital control (DDC), building automation systems (BAS), energy management systems (EMS), facility management systems (FMS), and other terms are used to describe these control systems.. These controls are capable of providing precise and dependable control of HVAC systems.. Digital controls can provide control strategies and energy conserving features not possible with any other control system type.. The collected information is used by the system to perform complex calculations which determine control command outputs for optimal operation.. Inputs Sensors collect information from the system and use them as inputs to a digital controller which uses this information to make decisions about the control of the system.