 Home
 Products
 Integration
 Tutorial
 Barcode FAQ
 Purchase
 Company
barcode reader integration with asp.net where G(z) = G,Gh(z> We may also obtain from Fig. 27.3 in Software
where G(z) = G,Gh(z> We may also obtain from Fig. 27.3 USS Code 128 Recognizer In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. Code 128A Creator In None Using Barcode generation for Software Control to generate, create Code 128 image in Software applications. UG,(z) Code 128 Code Set A Scanner In None Using Barcode scanner for Software Control to read, scan read, scan image in Software applications. Code 128 Code Set B Maker In Visual C#.NET Using Barcode printer for .NET Control to generate, create Code 128C image in VS .NET applications. E(z) = 1 + G(z)D(z)  1 + G(z)D(z) Code128 Drawer In .NET Framework Using Barcode encoder for ASP.NET Control to generate, create Code128 image in ASP.NET applications. Code 128A Creation In Visual Studio .NET Using Barcode drawer for VS .NET Control to generate, create Code 128 Code Set B image in .NET framework applications. (27.11) Paint USS Code 128 In Visual Basic .NET Using Barcode encoder for VS .NET Control to generate, create Code 128 Code Set A image in .NET framework applications. Code 128 Code Set B Drawer In None Using Barcode printer for Software Control to generate, create Code 128 Code Set C image in Software applications. C(z) = R(z)  E(z) Combining Eqs. (27.11) and (27.12) gives
USS128 Creation In None Using Barcode creation for Software Control to generate, create EAN 128 image in Software applications. Print UCC  12 In None Using Barcode drawer for Software Control to generate, create UPCA Supplement 2 image in Software applications. (27.12) Code39 Creator In None Using Barcode creator for Software Control to generate, create Code 39 Full ASCII image in Software applications. Painting Data Matrix ECC200 In None Using Barcode creator for Software Control to generate, create Data Matrix 2d barcode image in Software applications. G(zP(z)R(z) +
Printing ISSN In None Using Barcode printer for Software Control to generate, create ISSN image in Software applications. DataMatrix Encoder In Visual C#.NET Using Barcode generation for .NET framework Control to generate, create DataMatrix image in .NET framework applications. ( ) = 1 + G(z)D(z) Print UPC A In None Using Barcode creation for Font Control to generate, create GS1  12 image in Font applications. Scan Code39 In Visual C#.NET Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications. UG,(z) Code128 Creator In .NET Using Barcode generator for .NET framework Control to generate, create ANSI/AIM Code 128 image in VS .NET applications. ANSI/AIM Code 128 Creation In ObjectiveC Using Barcode generator for iPhone Control to generate, create Code 128B image in iPhone applications. 1 + G(z)D(z) UPC Code Printer In None Using Barcode drawer for Online Control to generate, create UPCA image in Online applications. Paint 1D Barcode In .NET Framework Using Barcode encoder for ASP.NET Control to generate, create 1D Barcode image in ASP.NET applications. (27.13) SAMPLEDDATA CONTROL SYSTEMS
Note that R(z) in Eqs. (27.11) and (27.13) is not bound to other transfer functions. This can be advantageous in design computations. Design Methods
It is convenient to design D(z) for a load change or a setpoint change. For a given disturbance in load or set point, the designer proposes a desired response at sampling instants, which means that C(nT) must be specified. This desired response will be written as Cd. From the desired response Cd(nT), one obtains Cd(z). Consider the case of only a load disturbance, i.e., R(z) = 0. Solving Eq. (27.13) for D(z) and replacing C by Cd to indicate that the desired response of C has been selected by the designer give D(z)= &[$$$l] (Design equation for load change) (27.14) Equation (27.14) is the equation to be used to design D(z) for a load change. In a similar manner, one can obtain from Eq. (27.13) a design equation for set point change, i.e. U(z) = 0. The result is Cd(Z) D(z) = G(z)[R(z)  cd(z)] (Design equation for setpoint change) (27.15) It is necessary that the highest power of z in the numerator of D(z) not exceed the highest power of z in the denominator. If this restriction is not satisfied, the algorithm will require knowledge of the future values of the error, i.e., prediction. An algorithm not satisfying this restriction is called unrealizable. Note that Eq. (27.4) is written in such a form that it does not admit the case where the highest power of z in the numerator exceeds the highest power of z in the denominator. If an unrealizable D(z) is obtained, we obtain the expression given by Eq. (27.4) multiplied by some positive power of z . To show how the control algorithms are obtained, several detailed examples that apply to Fig. 27.3 will be presented. Example 27.1. (T = UT, fast sampling, load) With regard to Fig. 27.3, consider the design of D(z) for T = a~. This relation between the sampling period and the process transport lag will be referred to as fast sampling. Later, an example involving slow sampling will be considered, in which T > aT. Consider a unitstep change in load to enter the system at an instant of sampling. The Ztransform of the output can be written in general form: (27.16) c,(z) = 170 + qlz + 72z* + * where the coefficients (7/i) correspond to the desired outputs of the system at sampling instants. It is the task of the designer to specify a desired output that leads to a realizable algorithm and fulfills the performance specifications listed earlier. In some cases, the nature of the physical process being controlled will aid in choosing a suitable Cd(Z) as expressed by Eq. (27.16). DESIGN
OF SAMPLEDDATA CONTROLLERS
The response diagram in Fig. 27.4 will help explain how the output C,(z) is selected by the designer. Because the transport lag in Gp(s) is one sampling period T, the output will remain at 0 for the first two sampling instants, that is, c(O) = 0, c(T) = 0 The response of c, which is the usual firstorder exponential rise starting at t = T, will reach 1  emTk at t = 2T, that is, (27.17) c(2T) = 1  edT r = 1  b where b = e . The control algorithm in D(z) cannot start to respond until t = 2T, at which time the error e has become  (1  b). The value of the manipulated variable m c generated by the algorithm at t = 2T will depend on the actual algorithm used. However, regardless of the value of m, at t = 2T, c will not change its course until t = 3T because of the transport lag emTS. The output of c from t = 2T to t = 3T will continue as an exponential rise and reach 1  e2T r at t = 3T, that is, c(3T) = 1  e 2Th = 1 _ b2 After t = 3T, the designer is free to choose any values of c at sampling instants. If c is chosen as zero at sampling instants beyond t = 3T, the resulting algorithm will be called a minimal prototype algorithm because the output returns to the set point in a minimum number of sampling periods. The response shown in Fig. 27.4 illustrates the minimal prototype response for a unitstep change in load. l b2 LLL 1b     

