Micro System SIMATIC S7-200.pdf (digital electronic circuits)

s Micro System SIMATIC S7-200 Two Hour Primer Edition 01/2000 Safety Guidelines The Two Hour Primer was created as a quick introduction to the world of S7-200 and has deliberately been kept short. It is not a substitute for the S7-200 manual. Therefore, please observe the instructions given in the S7-200 manual, especially the safety guidelines. Trademarks ® ® SIMATIC and SIMATIC NET are registered trademarks of Siemens AG. Third parties using for their own purposes any other names in this document which refer to trademarks might infringe upon the rights of the trademark owners. Copyright © Siemens AG 2000 All rights reserved Disclaimer of Liability The reproduction, transmission or use of this document or its contents is not permitted without express written authority. Offenders will be liable for damages. All rights, including rights created by patent grant or registration of a utility model or design, are reserved. We have checked the content of this manual for agreement with the hardware and software described. Since deviations cannot be precluded entirely, we cannot guarantee full agreement. However, the data in this manual are reviewed regularly and any necessary corrections included in subsequent editions. Suggestions for improvement are welcomed. Siemens AG Automation and Drives Industrial Automation Systems P.O. Box 4848, D-90327 Nuremberg Federal Republic of Germany Siemens Aktiengesellschaft © Siemens AG 2000 Subject to change without prior notice Order number: 6ZB5310-0FG02-0BA2 3UDFWLFHH[DPSOHV Practice examples for the 2 Hour Primer can be found in the directory: "PRIM_200/2H_EX/" Contents Revision A Few Words of Revision Here are the Bits Current Flow in the Ladder Diagram The PLC Cycle5 Latching Introduction Normally-Closed (NC) Contact Solution Description and Test A Different Take on Latching... 13 14 16 17 Introduction Solution Overview Edge Detection Bit Memories Solution Description and Test 21 22 23 25 27 Introduction Save As... Insert Network Solution Description Enter Comments 29 31 32 33 36 Introduction Basics Working with Sequencers Modification Solution Description, Example Test 39 41 45 50 51 55 Appendix Index A1 B1 Pulse-Operated Switch Off-Delay Timer Sequencer Appendix 5 6 7 9 You will find this breakdown of the TwoHour Primer in the footer of each page. The chapter you are currently in is highlighted in each case. 71 Preface Dear S7-200 user, Efficiency in the use of micro controllers depends primarily on how quickly and safely you can learn to use a controller. We created the 1-and 2-hour primers so that even beginners can learn to handle the S7-200 quickly and easily. Building on the 1-hour primer, this 2-hour primer will familiarize you in a short time with the principle of operation of the S7-200 controller. Using a few example tasks, the primer shows you how the controller operates and how it can be used effectively for simple tasks. After working through the 2-hour primer, you will find it easy to solve typical controller tasks on your own. Enjoy reading your primer! You can load the examples mentioned above from the enclosed diskette. The S7-200 team wishes you every success! Revision Latching Pulse-Operated Switch Off-Delay Timer Sequencer Appendix 1 2 Revision Latching Pulse-Operated Switch Off-Delay Timer Sequencer Appendix Chapter Chapter header - New, current Chapter logo Primer symbols Certain symbols and text highlights are used frequently in the 2-hour primer. Their meanings are explained on this page. Check out the page header first! Each page has an identical page header design. The blue heading in large letters indicates the current sub-header of the chapter. The area "New" in the righthand side of the header shows the contents of the preceding pages with the contents of the current page highlighted in blue followed by the contents of the following page(s). Text on a gray background prompts you to some action such as an input. 8 8 This symbol shows you that the left mouse key must be clicked once for an action (e.g. mark field). 2x © Ë F2 $ This symbol shows you that the left mouse key must be double-clicked for an action. Here you are prompted to press the ENTER (or RETURN) key on your keyboard. This indicates that you can select list points provided onscreen using the mouse or optionally the keyboard (function keys, arrow keys). This means you must press function key "F2" (function keys F1 ... F12 are available). You will discover that, despite user-friendly mouse operation, you can work faster with the keyboard in certain cases. In combination with a page reference, you will find here further details on a specific topic. ? At these points, you will be requested to make entries in text fields on the screen, or you will be reminded that in your own projects you should make notes here. Í Menu A menu point on the screen is activated step-by-step (heading, sub-heading) with the left mouse key. Revision Latching Pulse-Operated Switch Off-Delay Timer Sequencer Appendix 3 4 Revision Latching Pulse-Operated Switch Off-Delay Timer Sequencer Appendix Revision What you know already... - A Few Words of Revision Here are the Bits Current Flow in the Ladder Diagram The PLC Cycle A Few Words of Revision ... In the 1-hour primer, you saw that the circuit diagram for contactor controllers is related to the ladder diagram for programming programmable controllers. It is simply a representation with other symbols. In addition, you were already able to program small logic operations yourself. You even learned to recognize timers in that short time. Compare with Page 24 in the 1-hour primer Power rail phase Revision Latching Pulse-Operated Switch Off-Delay Timer Sequencer Appendix 5 Revision What you know already... - A Few Words of Revision Here are the Bits Current Flow in the Ladder Diagram The PLC Cycle Here are the Bits The smallest unit to be processed is the bit! The bit can assume two states: 1) "1" meaning "bit set" or state is "true", 2) "0" meaning "bit not set " or state is "untrue", In a method familiar to you, the two binary states "1" and "0" can be represented as electrical circuits, that is, they can be represented by switches. A closed switch: Current flows so bit state = "1" "1" ="true" = Current flows and an open switch: No current flows so bit state = "0". "0" = "untrue" = No current flows From here it requires only a short step to the representation of logic operations as circuits, e.g. series connection of two contacts. The AND operation of inputs I0.0 and I0.1 is represented as shown on the right. AND operation This is represented as follows in LAD: Finally, a small convention. The following applies for positive logic: 24V = high-level = "1" und 0V = low-level = "0". The following applies for negative logic: 0V = low-levgel = "1" 24V = high-level = "0". 6 Revision Latching positive logic negative logic Pulse-Operated Switch Off-Delay Timer Sequencer Appendix

Micro System SIMATIC S7-200

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