Manuale d’uso / di manutenzione del prodotto Module B3 del fabbricante Siemens
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A utomation and Drive s - SCE T I A Training Document Page 1 of 64 Module Training Document for Comprehensive Automation Solutions Totally Integrated Automation (T I A) MODULE B3 Control Engineering w.
A utomation and Drive s - SCE T I A Training Document Page 2 of 64 Module This document has been written by Siemens AG for tr aining purposes for the project entitled "Siemens Automation Cooperates with Education (SCE)". Siemens AG accepts no responsibility fo r the correctness of the contents.
A utomation and Drive s - SCE T I A Training Document Page 3 of 64 Module Table of Contents PAGE 1. Preface 5 2. Fundamentals of Control Engineering 7 2.2 Components of a Control Loop 8 2.3. Characteristics 11 2.4 Step Function for Examining Controlled Systems 12 2.
A utomation and Drive s - SCE T I A Training Document Page 4 of 64 Module The follow ing symbols prov ide a guide through this B3 module: Information Programming Exercise Example Notes B3 Issued: 02/2.
A utomation and Drive s - SCE T I A Training Document Page 5 of 64 Module 1. PREFACE Preface Fundamentals Discontinuous Acti on Controllerr Controller Block (S)FB41 Setting the System Appendix In terms of its contents, Module B3 is part of the teaching unit entitled "Additional Functions of STEP 7 Programming' .
A utomation and Drive s - SCE T I A Training Document Page 6 of 64 Module Hardw are and softw are required 1 PC, operating system Windows 2000 Professional starting with SP4/XP Professional starting with SP1/Server 2003 with 600MHz and 512RAM, free hard disk storage 650 to 900 MB, MS Internet Explorer 6.
A utomation and Drive s - SCE T I A Training Document Page 7 of 64 Module 2. FUNDAMENTALS OF CONTROL ENGINEERING 2.1 Tasks of Control Engineering "Closed loop control is a process where the va lue of a variable is established and maintained continuously through intervention based on measurements of this variable.
A utomation and Drive s - SCE T I A Training Document Page 8 of 64 Module 2.2 Components of a Control Loop Below, the basic terminology of cont rol engineering is explained in detail. First, an overview shown in the diagram below: Measuring Device Controlled System Final Control Element Actuator Controlling Element Comparing Element Controller 1.
A utomation and Drive s - SCE T I A Training Document Page 9 of 64 Module 4. The Disturbance Variable z The disturbance variable is the variable that unint entionally influences the controlled variable, and moves it from the current setpoint value. A fix ed setpoint control is necessary, for example, because a disturbance variable exists.
A utomation and Drive s - SCE T I A Training Document Page 10 of 64 Module 8. The Actuator The actuator is the “executing organ“, so to speak, of the control system.
A utomation and Drive s - SCE T I A Training Document Page 11 of 64 Module 2.3. Characteristics Controlled systems in which a new constant output value sets itself after a certain time has passed are called 'self-regulating process’.
A utomation and Drive s - SCE T I A Training Document Page 12 of 64 Module 2.4 Step Function for Examining Controlled Systems To examine the behavior of contro lled systems, controllers and cont rol loops, a uniform function is used for the input signal: the step function.
A utomation and Drive s - SCE T I A Training Document Page 13 of 64 Module 2.5. Self-Regulating Processes 2.5.1. Proportional Controlled System without Time Delay The controlled system is called P-sy stem for short.
A utomation and Drive s - SCE T I A Training Document Page 14 of 64 Module 2.5.2. Proportional Controlled System with a Time Delay The controlled system is called P-T1 system for short.
A utomation and Drive s - SCE T I A Training Document Page 15 of 64 Module 2.5.3 Proportional Controlled System with Tw o Time Delays The controlled system is called P-T2 system for short.
A utomation and Drive s - SCE T I A Training Document Page 16 of 64 Module 2.5.4 Proportional Controlled System with n Time Delays The controlled system is called P-Tn system for short. The time response is described with a differential equation of the nth degree.
A utomation and Drive s - SCE T I A Training Document Page 17 of 64 Module 2.6 Controlled Systems without Inherent Regulation The controlled variable continues to grow after a fault, without aiming for the high range value.
A utomation and Drive s - SCE T I A Training Document Page 18 of 64 Module 2.7 Types of Controllers 2.7.1 Tw o Position Controllers The essential feature of two position controllers consists of their know ing only two modes: “On“ and “Off“ -which makes them the simplest type of c ontroller.
A utomation and Drive s - SCE T I A Training Document Page 19 of 64 Module The diagram below shows a two position controller: Controlled Variable Time Switch-On Value Manipulated Variable Time Setpoin.
A utomation and Drive s - SCE T I A Training Document Page 20 of 64 Module 2.7.2 Three Position Controllers The three position controllers represent the se cond important class of discrete controllers.
A utomation and Drive s - SCE T I A Training Document Page 21 of 64 Module 2.7.3 Basic Types of Continuous Controllers The discrete controllers just discussed have, as mentioned before, the advantage of being simple.
A utomation and Drive s - SCE T I A Training Document Page 22 of 64 Module 2.7.3.1 Proportional Controllers (P-Controller) In the case of a P-controller, the controller output y is always proportional to the recorded system deviation (y ~ e).
A utomation and Drive s - SCE T I A Training Document Page 23 of 64 Module The figure below shows the performance of the P-controller: Time System Deviation Setpoint A ctual Value Controlled Variable .
A utomation and Drive s - SCE T I A Training Document Page 24 of 64 Module 2.7.3.2 Integral Action Controllers (I- Controller) Integrating controllers are used to completely corre ct system deviations at every operating point. As long as the system deviation is not equal to zero , the amount of the controller output changes.
A utomation and Drive s - SCE T I A Training Document Page 25 of 64 Module 2.7.3.3 PI Controllers In practice, the PI controller is a controller type that is used very often. It consists of the parallel connection of a P-controller and an I-controller.
A utomation and Drive s - SCE T I A Training Document Page 26 of 64 Module 2.7.3.4 Derivative Action Controllers (D-Controller) The D-controller generates its controller output from the rate of change of the system deviation, and not -like the P-controller- from its amplitude.
A utomation and Drive s - SCE T I A Training Document Page 27 of 64 Module 2.8 Objectives for Controller Adjustment For a satisfactory control result , selecting a su itable controller is an important aspect.
A utomation and Drive s - SCE T I A Training Document Page 28 of 64 Module - Note down the Kp value that has been set as the critical proportional coefficient. - Specify the duration of a complete oscillation as Tkrit, perhaps with a stop watch by generating the arithmetical mean over several oscillations.
A utomation and Drive s - SCE T I A Training Document Page 29 of 64 Module 2.9 Digital Controllers So far, mainly analog controllers were discussed; t hat is, such controllers that derive the controller output variable -also in an analog way- from the existing system deviation that exists as analog value.
A utomation and Drive s - SCE T I A Training Document Page 30 of 64 Module The diagram below shows the lay out of a digital controller: ADC System Digital Controller DAC Comparing Element However, the digital conversion of the contro ller has not only advantages; this conversion also entails various problems.
A utomation and Drive s - SCE T I A Training Document Page 31 of 64 Module 3. DISCONTINUOUS ACTION CONTROLLE R AS TWO POSITION CONTROLLER 3.1 Function and Problem Description A process value (for example, the level) is to be kept as constant as possible with a discontinuous action controller.
A utomation and Drive s - SCE T I A Training Document Page 32 of 64 Module Structogram A structogram shows the rough structure of a pr ogram plan. The structogram below shows the possible structure of a program for a two position controller. First, a scan is made whether t he controller is switched on.
A utomation and Drive s - SCE T I A Training Document Page 33 of 64 Module Assignment List: Symbol: Address: Comment Start I 1.3 Button Start Stop I 1.
A utomation and Drive s - SCE T I A Training Document Page 34 of 64 Module 3.2 Possible Solution for the PLC Program: Analog Value Processing Network 1: Enter and normalize analog value of actual leve.
A utomation and Drive s - SCE T I A Training Document Page 35 of 64 Module Network 4 : Calculation of half differential X1 = Xs/2 "AI_Fill_Setp_Norm“ N etwork 5: Calculation of the low operating point Xu = w – X1 N etwork 6 : ACTUAL VALUE x less than low operating point? D24/AI_Fill_Setp_Norm/Norm.
A utomation and Drive s - SCE T I A Training Document Page 36 of 64 Module Network 9 : Reset values exit: "AI_Fill_Actual_Norm“ "AI _ Fill _ Setp _ Norm "Pump“ "Pump“ "D.
A utomation and Drive s - SCE T I A Training Document Page 37 of 64 Module 4. CONTROLLER BLOCK (S)FB41 "CONT_C" AS SOFTWARE PID CONTROLLER IN STEP 7 4.1 Task Definition for PID Standard Controller In this B3 module, the startup of a PID controller in SIMATIC S7 is demonstrated.
A utomation and Drive s - SCE T I A Training Document Page 38 of 64 Module Assignment List: Symbol: Address: Comment AI_w PEW 128 Analog input setpoint generator 0…10V AI_X PEW 130 Analog input sens.
A utomation and Drive s - SCE T I A Training Document Page 39 of 64 Module 4.2 (S) FB 41 “CONT_C“ (S)FB 41 "CONT_C“ (continuous controller) is us ed for controlling technical processes with continuous input and output variables on the PLC SIMATIC S7.
A utomation and Drive s - SCE T I A Training Document Page 40 of 64 Module Starting Up the Softw are PID Controller (S)FB41 "CONT_C" w ith STEP 7 A SIMATIC S7-300 is programmed as a PID controlle r with the software STEP 7. This provides the user with a uniform configuring tool for central as well as distributed configurations.
A utomation and Drive s - SCE T I A Training Document Page 41 of 64 Module 3. Generate a new project, select a path and assign a project name ( → User projects → PID_Control → OK) Enter project name Cick 'OK' Select storage location (path) Select 'User Projects’ 4.
A utomation and Drive s - SCE T I A Training Document Page 42 of 64 Module 5. Highlight 'SIMATIC 300 Station(1)’. Click on 'SIMATIC 300 Station(1)' 6.
A utomation and Drive s - SCE T I A Training Document Page 43 of 64 Module 7. Open the hardware catalog. Here, all racks, modules, and interface modules fo r configuring your hardware, are provided arranged in the directories: PROFIBUS-D P, SIMATIC 300, SIMA TIC 400 and SIMATIC PC Based Control.
A utomation and Drive s - SCE T I A Training Document Page 44 of 64 Module 9. From the hardware catalog, all modules that are plugged inserted in your real rack can now be selected and inserted in the confi guration table.
A utomation and Drive s - SCE T I A Training Document Page 45 of 64 Module 10. Note down the addresses of the IO modules (addresses are assigned automatically and tied to the slot ). For our example, change the addresses to the values PEW 128 and PAW 128.
A utomation and Drive s - SCE T I A Training Document Page 46 of 64 Module 12. Insert organization block. ( → Insert → S7 Block → Organization block) Click on 'Organization block’ 13.
A utomation and Drive s - SCE T I A Training Document Page 47 of 64 Module 14. In the hardware configuration, at Properties of the CPU, a fixed cycle time can be set for executing OB35.
A utomation and Drive s - SCE T I A Training Document Page 48 of 64 Module 16. With ‘LAD, STL, and FBD – Program S7 Blo cks’, you now have an editor that allows you to edit your STEP7 program accordingly. To this end, OB35 has already been opened with the first network.
A utomation and Drive s - SCE T I A Training Document Page 49 of 64 Module 17. The setpoint value, the actual value and the manipulated variable now have to be wired to process values as follows. Cycle time: Time between the block call. Should correspond to the time that is set in OB 35.
A utomation and Drive s - SCE T I A Training Document Page 50 of 64 Module 18. Save and load OB35 (CPU’s key switch is on Stop!) 19. In ‘SIMATIC Manager’, highlight block DB41 and load to the PLC.
A utomation and Drive s - SCE T I A Training Document Page 51 of 64 Module 20. Call the tool Assign parameters to the PID control ( → Start → Simatic → STEP 7 → Parameterize PID Control) Click.
A utomation and Drive s - SCE T I A Training Document Page 52 of 64 Module 21. Open data block ( → File → Open → Online → Select data block; for example, DB41 → OK).
A utomation and Drive s - SCE T I A Training Document Page 53 of 64 Module 22. The PID controller can now be parameterized with the tool Parameterize PID Control . Then, the DB is saved ( → Save) and loaded to the PLC ( → Load). Now, a curve plotter can be started in order to monitor the performance of the controlled system.
A utomation and Drive s - SCE T I A Training Document Page 54 of 64 Module 5. SETTING CONTROLLED SYSTEMS 5.1 General Below, setting controlled sy st ems is discuss ed, using a PT2 system as an example.
A utomation and Drive s - SCE T I A Training Document Page 55 of 64 Module 5.2 Setting the PI-Controller according to Ziegler-Nichols By experimenting with P-T 1 -T L systems, Ziegler and Nichols have found the following optimum controller settings for fixed setpoint control: K S T u T g K PR = 0, 9 T N = 3,33 T u 0.
A utomation and Drive s - SCE T I A Training Document Page 56 of 64 Module • For setpoint characteristic: Preface Fundamentals Di scontinuous Action Controller Controller Block (S)FB41 Setting the S.
A utomation and Drive s - SCE T I A Training Document Page 57 of 64 Module 5.4 Exercise Example To accommodate the system step response, a fe w modifications have to be made in OB 35 and DB41. The following steps have to be performed for this: Save your old project under a new name, and change the wiring of (S)FB 41 as follows: 1.
A utomation and Drive s - SCE T I A Training Document Page 58 of 64 Module Solution of the PLC program: Network 1 : Call PID Controller Wiring the manual value to thevalue 0 or 100% of the manipulated.
A utomation and Drive s - SCE T I A Training Document Page 59 of 64 Module Then, the system step response is recorded with the curve plotter from 0 to 100%.
A utomation and Drive s - SCE T I A Training Document Page 60 of 64 Module 6. APPENDIX Diagram of the controller block: Preface Fundamentals Discontinuous Action Controller Controller Block (S)FB41 Se.
A utomation and Drive s - SCE T I A Training Document Page 61 of 64 Module Input Parameters Parameter Data Type Value Range Default Description COM_RST BOOL FALSE COMPLETE RESTART. The block has a complete restart routine that is processed if the input is set to "Complete restart".
A utomation and Drive s - SCE T I A Training Document Page 62 of 64 Module Parameter Data Ty pe Value Range Default Description CYCLE TIME >= 1 ms T#1s SAMPLE TIME. The time between block calls has to be constant. T he input "Sample time" indicates the time between block calls.
A utomation and Drive s - SCE T I A Training Document Page 63 of 64 Module Parameter Data Type Value Range Default Description LMN_HLM REAL LMN_LLM... +100.0 % or phys. variable 2 100.0 MANIPULATED VALUE HIGH LIMIT. The manipulated value is always limited to a high and a low limit.
A utomation and Drive s - SCE T I A Training Document Page 64 of 64 Module Output Parameters: Parameter Data Type Value Range Default Description LMN REAL 0.0 MANIPULATED VALUE. At the output "Manipulated value", the effectively active manipul ated value is read out in the floating point format.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Siemens Module B3 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Siemens Module B3 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Siemens Module B3 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Siemens Module B3 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Siemens Module B3, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Siemens Module B3.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Siemens Module B3. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Siemens Module B3 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
