Automating witfi STEP7 in LAD and FBD

Transcription

1 Automating witfi STEP7 in LAD and FBD Programmable Controllers SIMATIC S7-300/400 by Hans Berger 2nd revised edition, 2001 Publicis MCD Corporate Publishing

2 Contents Contents Indroduction 19 1 SIMATIC S7-300/400 Programmable Controller Structure of the Programmable Controller Components S7-300 Station S7-400 Station CPU Memory Areas Memory Card System Memory Distributed I/O DP Master System DP Master DPSlaves Connection to PROFIBUS-PA Connection to AS-Interface Connection to a Serial Interface Communications Introduction Subnets Communications Services Connections Module Addresses Signal Path SlotAddress Module Start Address Diagnostics Address Addresses for Bus Nodes Address Areas User Data Area Process Image Bit Memory 38 2 STEP 7 Programming Software STEP 7 Basic Package Installation Authorization SIMATIC Manager Projects and Libraries Online Help Editing Projects Creating Projects Managing, Rearranging and Archiving Project Versions Configuring Stations Arranging Modules Addressing Modules Parameterizing Modules Networking Modules with MPI Monitoring and Modifying Modules Configuring the Network Configuring the Network View Configuring a DP Master System with the Network Configuration Configuring Connections Network Transitions Loading the Connection Data Creating the S7 Program Introduction Symbol Table Program Editor Updating or generating source files Address Priority Reference Data Multilangual Comments and Display Texts 64 12

3 2.6 Online Mode Connecting a PLC Protecting the User Program CPU Information Loading the User Program into the CPU Block Handling Testing the Program Diagnosing the Hardware Determining the Cause of a STOP Monitoring and Modifying Variables Forcing Variables Enabling Peripheral Outputs LAD/FBD Program Status SIMATIC S7 Program Program Processing Program Processing Methods Priority Classes Specifications for Prograrp Processing Blocks Block Types Block Structure Block Properties Block Interface Programming Code Blocks Generating blocks Editing LAD Elements Editing FBD Elements Programming Data Blocks Creating Blocks Types of Data Blocks Block Window Variables, Constants and Data Types General Remarks Concerning Variables Addressing Variables Overview of Data Types Elementary Data Types Complex Data Types Parameter Types User Data Types 106 Basic Functions Binary Logic Operations Series and Parallel Circuits (LAD) NO Contact and NC Contact Series Circuits Parallel Circuits Combinations of Binary Logic Operations Negating the Result of the Logic Operation Binary Logic Operations (FBD) Elementary Binary Logic Operations Combinations of Binary Logic Operations Negating the Result of the Logic Operation Taking Account of the Sensor Type Memory Functions LADCoils Single Coil Set and Reset Coil Memory Box FBDBoxes Assign Set and Reset Box Memory Box Midline Outputs Midline Outputs in LAD Midline Outputs in FBD Edge Evaluation How Edge Evaluation Works Edge Evaluation in LAD Edge Evaluation in FBD Binary Scaler Solution in LAD Solution in FBD Example of a Conveyor Control System 134

4 Contents 6 Move Functions General MOVE Box Processing the MOVE Box Moving Operands Moving Constants System Functions for Data Transfer ANY Pointer Copy Data Area Uninterruptible Copying of a DataArea Fill Data Area Timers Programming a Timer General Representation of a Timer Starting a Timer Specifying the Duration of Time ResettingA Timer Checking a Timer Sequence of Timer Operations Timer Box in a Rung (LAD) Timer Box in a Logic Circuit (FBD) Pulse Timer Extended Pulse Timer On-Delay Timer Retentive On-Delay Timer Off-Delay Timer IEC Timers Pulse Timer SFB 3 TP On-Delay Timer SFB 4 TON Off-Delay Timer SFB 5 TOF Counters Programming a Counter Setting and Resetting Counters Counting Checking a Counter IEC Counters Up Counter SFB 0 CTU Down Counter SFB 1 CTD Up/down Counter SFB 2 CTUD Parts Counter Example 161 Digital Functions Comparison Functions Processing a Comparison Function Description of the Comparison Functions Arithmetic Functions Processing an Arithmetic Function Calculating with Data Type INT Calculating with Data Type DINT Calculating with Data Type REAL Mathematical Functions Processing a Mathematical Function Trigonometrie Functions Are Functions Miscellaneous Mathematical Functions Conversion Functions Processing a Conversion Function Conversion of INT and DINT Numbers Conversion ofbcd Numbers Conversion of REAL Numbers Miscellaneous Conversion Functions Shift Functions Processing a Shift Function Shift Rotate

5 14 Word Logic Processing a Word Logic Operation Description of the Word Logic Operations 193 Program Flow Control Status Bits Description of the Status Bits Setting the Status Bits Evaluating the Status Bits Using the Binary Result Setting the Binary Result BR Main Rung, EN/ENO Mechanism ENO in the Case of User-written Blocks Jump Functions Processing a Jump Function Unconditional Jump JumpifRLO = "l" JumpifRLO = "0" Master Control Relay MCR Dependency MCRArea MCR Zone Setting and Resetting I/O Bits Block Functions Block Functions for Code Blocks Block Calls: General Call Box CALLCoil/Box Block End Function Temporary Local Data Static Local Data Block Functions for Data Blocks Two Data Block Registers Accessing Data Operands Opening a Data Block Special Points in Data Addressing System Functions for Data Blocks Creating a Data Block Deleting a Data Block Testing a Data Block Block Parameters Block Parameters in General Defining the B lock Parameters Processing the Block Parameters Declaration of the Block Parameters Declaration of the Function Value Initializing Block Parameters Formalparameters Actual Parameters ' 'Forwarding' 'Block Parameters Examples Conveyor Belt Example Parts Counter Example Feed Example 233 Program Processing Main Program Program Organization Program Structure Program Organization Scan Cycle Control Process Image Updating Scan Cycle Monitoring Time Minimum Scan Cycle Time, Background Scanning Response Time Start Information Program Functions Real-Time Clock Read System Clock Run-Time Meter Compressing CPU Memory Waiting and Stopping Multiprocessing Mode 252

6 Contents 20.4 Communication via Distributed I/O Addressing Distributed I/O Configuring Distributed I/O System Functions for Distributed I/O Global Data Communication Fundamentals Configuring GD communication System Functions for GD Communication SFC Communication Station-Internal SFC Communication System Functions for Data Interchange Within a Station Station-External SFC Communication System Functions for Station- External SFC Communication SFB Communication Fundamentals Two-Way Data Exchange One-Way Data Exchange Transferring Print Data Control Functions Monitoring Functions Interrupt Handling General Remarks Hardware Interrupts Generating a Hardware Interrupt Servicing Hardware Interrupts Configuring Hardware Interrupts wifh STEP Watchdog Interrupts Handling Watchdog Interrupts Configuring Watchdog Interrupts with STEP Time-of-Day Interrupts Handling Time-of-Day Interrupts Configuring Time-of-Day Interrupts with STEP System Functions for Time-of-Day Interrupts Time-Delay Interrupts Handling Time-Delay Interrupts Configuring Time-Delay Interrupts with STEP System Functions for Time-Delay Interrupts Multiprocessor Interrupt Handling Interrupts Restart Characteristics General Remarks Operating Modes HOLD Mode Disabling the Output Modules Restart Organization Blocks Power-Up STOP Mode Memory Reset Retentivity Restart Parameterization Types of Restart START-UPMode Cold Restart Complete Restart Warm Restart Ascertaining a Module Address Parameterizing Modules Error Handling Synchronous Errors Synchronous Error Handling Error Filters Masking Synchronous Errors Unmasking Synchronous Errors Reading the Error Register Entering a Substitute Value Asynchronous Errors

7 23.4 System Diagnostics Diagnostic Events and Diagnostic Buffer Writing User Entries in the Diagnostic Buffer Evaluating Diagnostic Interrupts Reading the System Status List. 318 Appendix Supplements to Graphic Programming Block Protection Indirect Addressing Pointers: General Remarks Area Pointer DB Pointer ANY Pointer "Variable" ANY Pointer Brief Description of the "Message Frame Example" Block Libraries Organization Blocks System Function Blocks IEC Function Blocks S5-S7 Converting Blocks TI-S7 Converting Blocks PID Control Blocks Communication Blocks Function Set LAD Basic Functions Digital Functions Program Flow Control Function Set FBD Basic Functions Digital Functions Program Flow Control 340 Index 341 Abbreviations 347 STEP 7 Demo Software 348