SCADA Expert Vijeo Citect 2015 Programming with Cicode Study Guide

Transcription

1 SCADA Expert Vijeo Citect 2015 Programming with Cicode Study Guide 2015 Schneider-Electric Pty (Australia) Ltd 78 Waterloo Road Macquarie Park NSW 2113 Australia

2 DISCLAIMER Schneider Electric makes no representations or warranties with respect to this study guide and, to the maximum extent permitted by law, expressly limits its liability for breach of any warranty that may be implied to the replacement of this study guide with another. Furthermore, Schneider Electric reserves the right to revise this publication at any time without incurring an obligation to notify any person of the revision. The information provided in this documentation contains general descriptions and/or technical characteristics of the performance of the products contained herein. This documentation is not intended as a substitute for and is not to be used for determining suitability or reliability of these products for specific user applications. It is the duty of any such user or integrator to perform the appropriate and complete risk analysis, evaluation and testing of the products with respect to the relevant specific application or use thereof. Neither Schneider Electric nor any of its affiliates or subsidiaries shall be responsible or liable for misuse of the information that is contained herein. If you have any suggestions for improvements or amendments or have found errors in this publication, please notify us. All pertinent state, regional, and local safety regulations must be observed when installing and using this product. For reasons of safety and to help ensure compliance with documented system data, only the manufacturer should perform repairs to components. When devices are used for applications with technical safety requirements, the relevant instructions must be followed. Failure to use Schneider Electric software or approved software with our hardware products may result in injury, harm, or improper operating results. Failure to observe this information can result in injury or equipment damage Schneider Electric. All rights reserved. INTRODUCTION AND LEGAL NOTICE Satisfactory completion of the course evaluation is mandatory for you to obtain a Schneider Electric certificate of completion of the training course. The contents of this study guide are proprietary to Schneider Electric and all rights, including copyright, are reserved by Schneider Electric. No part of this document may be reproduced in any form or by any means, electronic or mechanical, including photocopying, without express written permission of Schneider Electric. Schneider Electric will not accept any liability for action taken in reliance on this training study guide. TRADEMARKS Schneider Electric has made every effort to supply trademark information about company names, products and services mentioned in this study guide. Trademarks shown below were derived from various sources. Vijeo Citect, CitectSCADA, Cicode, Vijeo Historian, CitectHistorian, and Ampla are trademarks owned by Schneider Electric Industry SAS or its affiliated companies. All other trademarks are the property of their respective owners. ActiveX, Excel, Internet Explorer, Microsoft.NET, SQL Server, Windows, Windows Server, Windows XP, Windows Vista, Windows 7 and Windows 8 are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. SafeNet Sentinel is a trademark of Sentinel, Inc. VMware is a registered trademark or trademark of VMware, Inc. in the United States and/or other jurisdictions. General Notice: Some product names used in this study guide are used for identification purposes only and may be trademarks of their respective companies. Validity Note The present documentation is intended for qualified technical personnel responsible for the implementation, operation and maintenance of the products described. It contains information necessary for the proper use of the products. Electrical equipment should be installed, operated, serviced, and maintained only by qualified personnel. No responsibility is assumed by Schneider Electric for any consequences arising out of the use of this material. A qualified person is one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. June 2015 Edition for Vijeo Citect 2015 ii Vijeo Citect Cicode Exam

3 Contents CHAPTER 1: 2015 CICODE PROGRAMMING EXAM TOPICS OVERVIEW Function Structure Variables, Datatypes and Data Structures Flow Control Logic Statements Input and Output Parameter Passing Error Handling Debugging Programming Standards Vijeo Citect Cicode Exam iii

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5 Chapter 1: 2015 Cicode Programming Exam Topics Overview Introduction Cicode Programming is the second of the CSCE exams. This exam is based around information that is covered in the Cicode Programming Course. This Chapter Covers These Topics: Function Structure Variables, Datatypes and Data Structures Flow Control Logic Statements Input and Output Parameter Passing Error Handling Debugging Programming Standards Vijeo Citect Cicode Exam 1-1

6 Cicode Development Environment Programming Language Cicode is a simple, easy-to-use computer programming language designed especially for plant monitoring and control applications. It is a structured language similar to Visual Basic or 'C', however you need no previous programming experience to use it. Using Cicode, you have access to all real-time data (variables) in the Vijeo Citect project, and all Vijeo Citect facilities - variable tags, alarms, trends, reports, and so on. You can use Cicode to interface to various resources on the computer, such as the operating system and communication ports. Cicode supports advanced features including pre-emptive multi-tasking, multi-threads, and remote procedure calls that will be discussed later in this course. Create and save Cicode function libraries. Experiment with the automated layout functionality within the editor. Use comments to disable sections of cicode. Vijeo Citect Help Topic - The Cicode Editor. 1-2 Vijeo Citect Cicode Exam

7 Function Structure User Functions Vijeo Citect is supplied with over 600 in-built functions. One or a combination of these functions can usually perform most tasks in your system. However, where system functionality cannot be achieved with in-built functions, you can write your own functions. A Cicode function is a small program that may contain a collection of statements, variables, operators, conditional executors, and functions, in fact, of all the elements of Cicode. Revise the syntax of Cicode functions. Make a small Cicode program to create a standard Microsoft ActiveX Listbox at runtime, and fill this listbox with three items, and then select one of these items, and then store the value of the item in a DiskPLC variable. Vijeo Citect Help Topic - Cicode Function syntax. Vijeo Citect Help Topic - Converting and Formatting Cicode Variables. Vijeo Citect Cicode Exam 1-3

8 Variables, Datatypes and Data Structures Operators Cicode is used to manipulate data and perform tasks. Data manipulation is achieved using five classes of operators. These are the Mathematical, Bit, Logical, Relational and Format operators. Review the Cicode Programming Training manual. Create Global, Module and Local variable declarations along with assigning default values to the declared variables. Determine maximum array size limits. Vijeo Citect Help Topic - Using Variables. Vijeo Citect Help Topic - Using Arrays. Vijeo Citect Help Topic - Variable declaration. 1-4 Vijeo Citect Cicode Exam

9 Flow Control Four Conditional Executors The statements that control decisions and loops in your functions are called conditional executors. Cicode uses four conditional executors: IF, FOR, WHILE and SELECT CASE. Review the syntax of the four types of Conditional Executor in Cicode. Create functions that test the functionality of the Conditional Executors. Vijeo Citect Help Topic - Working with Conditional Executors. Vijeo Citect Cicode Exam 1-5

10 Logic Use of Logic in Cicode Cicode supports the use of all major Logical operators: AND, OR, XOR, NOT. Create simple logic statements to test the order of precedence and also to be sure that you understand how statements are executed. Vijeo Citect Help Topic - Using Logical Operators 1-6 Vijeo Citect Cicode Exam

11 Statements Doing the Work Statements are used to execute Cicode Functions and also to assign values (or the results of Cicode Functions) to variables and to Variable Tags. Statements also include the ability to exchange information between variable of differing datatypes - for instance converting an Integer to a String or vice versa. The various operators (addition, subtraction, multiplication etc) have an order of precedence (they are not executed left-to-right or right-to-left) Review the Order of Precedence of Operators. Create Cicode fragments to assign values and call functions. Confirm your knowledge of datatype conversion functions. Vijeo Citect Help Topic - Working with Operators. Vijeo Citect Help Topic - Converting and Formatting Cicode Variables. Vijeo Citect Help Topic - Order of Precedence of Operators. Vijeo Citect Cicode Exam 1-7

12 Input and Output Interact with the Operator In addition to acting on data sourced from the plant via Variable Tags, there are occasions when it is necessary to interact with the operator in order to either request values (perhaps the name of the next recipe or the adjusted setpoint value for some parameter) or to provide other information - often via the prompt field on the screen. Generally, the Input and the Prompt Cicode functions are used for this, although others are also available. Understand the datatype of the various input and output functions and be familiar with how to ensure data is sent or received in the necessary datatype. Be familiar with key sequences for data input. Test the use of the ArgX and ArgValueX items. Vijeo Citect Help Topic - Defining Key Sequences for Commands. Vijeo Citect Help Topic - Input. Vijeo Citect Help Topic - Prompt. Vijeo Citect Help Topic - FormNumPad. 1-8 Vijeo Citect Cicode Exam

13 Parameter Passing Provide Information for a Function to work with In order to make Cicode Functions flexible and reusable, it is normal to provide a list of parameters for them to work with as arguments to the function. Clearly the only alternative would be to define some large list of fixed Global variables. When passing parameters to a function, the programmer must make sure that the parameters appear in the correct order and have the proper datatypes. Create Cicode Functions with default parameters for use when the parameter is not provided. Call functions with missing parameters. Test the application of datatypes to function parameters. Vijeo Citect Help Topic - Parameters. Vijeo Citect Help Topic - Function Argument Structure. Vijeo Citect Cicode Exam 1-9

14 Error Handling Deal with Problems There are many situations where your programs must handle unexpected events. These might range from a file not existing when you request to open it to attempting to read from a non-existent array item. You should write your software to minimise these issues as much as possible and also to gracefully handle the ones you can't catch. Vijeo Citect Help Topic - Defensive Programming. Vijeo Citect Help Topic - Using Cicode Programming Standards Vijeo Citect Cicode Exam

15 Debugging Cicode Editor as a Debugger The Cicode Editor can function in debug mode, to analyse running Cicode. Debugging Cicode requires that Vijeo Citect is running, though you can turn debugging on and off as required. The operation of the debugger is controlled through Debug Options, with some options only taking effect on startup. Review how the Cicode language supports multi-tasking and pre-empting. Review the use of the Cicode Editor in Debug mode. Add some breakpoints to the program you created earlier and use the Cicode debugger to step through it, by breakpoint and line by line. Vijeo Citect Help Topic - Debugging Cicode. Vijeo Citect Help Topic - Using breakpoints. Vijeo Citect Help Topic - Stepping through code. Vijeo Citect Cicode Exam 1-11

16 Programming Standards Fundamentals of Good Design One of the critical aspects to follow on from the earlier concepts of Error Handling and Defensive Programming is "Good Design." the better designed your software is, the easier it will be to deal with errors and exceptions. Software should be written with as much of the code hidden as PRIVATE functions in order to not accidentally call functions which have not been configured for global use. Similarly, unless a variable must be made available globally, it should be declared as a MODULE variable or even kept local to a function. Experiment with declaring PUBLIC and PRIVATE Functions. Investigate the difference between Blocking and Non-Blocking functions. Read widely on programming techniques. Vijeo Citect Help Topic - Function Scope. Vijeo Citect Help Topic - Formatting Functions Vijeo Citect Cicode Exam