subject: Simatic S5 PLC - CP-60 Current Probe - HUS-1000 Test Bench [print this page] Simatic S5 PLC - CP-60 Current Probe - HUS-1000 Test Bench
To maintain maximum transparency, STEP 5 offers a number of structuring facilities: Block technique - A linear operation sequence is divided into sections and packed into individual blocks. Segments - Within blocks, fine structuring is possible by programming subtasks in individual segments. Comments - Both a complete program as well as individual blocks or segments and individual statements can be directly provided with comments. Methods of representation STEP 5 programs can be represented in three different ways: Statement List (STL) - The program consists of a sequence of mnemonic codes of the commands executed one after another by the PLC. Ladder Diagram (LAD) - Graphical representation of the automation task with symbols of the circuit diagram Function Block Diagram (FBD) - Graphical representation of the automation task with symbols to DIN 40700/ DIN 40719. Absolute or symbolic designations can be used for operands with all three methods of representation. In LAD and FBD complex functions and function block calls can be entered via function keys. They are displayed on the screen as graphical symbols. Blocks Five types of blocks are available: Organization blocks (OB) - for managing the control program Programming blocks (PB) - contain the control program structured according to functional or process-oriented characteristics Sequence blocks (SB) - for programming sequential controls Function blocks (FB) - contain frequently occurring and particularly complex program parts Data blocks (DB) - for storing data required for processing the control program. Some S5 PLCs also have block types FX (Extended Function Blocks), and DX(Extended Data Blocks); these are not distinct block types, but rather are another set of available blocks due to the CPU having more memory and addressing space. Operations STEP 5 differentiates between three types of operations: Basic operations, (e.g. linking, saving, loading & transferring, counting, comparing, arithmetic operations, module operations) - These can be performed in all three representations. Supplementary operations and complex functions, (e.g. substitution statements, testing functions, word-by-word logic operations, decrement/increment and jump functions.) - These can only be executed in STL. System operations (direct access the operating system) - These can only be executed in STL. Additional functions Saving user-specific project settings Symbol editor Automatic generation and updating of cross-reference lists Comparison of user programs Transferring blocks to EPROM and EEPROM memory modules for programmable controllers Rewiring inputs, outputs, flags, timers and counters Testing and service functions for startup and maintenance External references Siemens S5 to S7 Migration Hans Berger - Automating with SIMATIC - ISBN 978-3-89578-333-3 Juergen Mueller -
