1.1 How to use this manual

The extensive function block library RexLib, which is a standard part of the REXYGEN system, is divided into smaller sets of logically related blocks, the so-called categories (sublibraries). A separate chapter is devoted to each category, introducing the general properties of the whole category and its blocks followed by a detailed description of individual function blocks.

The content of individual chapters of this manual is following:

  1. Introduction
    This introductory chapter familiarizing the readers with the content and ordering of the manual. A convention used for individual function blocks description is presented.
  2. EXEC – Runtime executive configuration
    Blocks used mainly for configuration of the structure, priorities and timing of individual objects linked to the real-time subsystem of the REXYGEN system (the RexCore program) are described in this chapter.
  3. INOUT – Input and output blocks
    This sublibrary consists of the blocks used mainly for the REXYGEN system. These blocks provide the connection between the control tasks and input/output drivers.
  4. MATH – Mathematic blocks
    The blocks for arithmetic operations and basic math functions.
  5. ANALOG – Analog signal processing
    The integrator, derivator, time delay, moving average, various filters, comparators and selectors can be found among the blocks for analog signal processing. The starting unit block (AVS) is also very interesting.
  6. GEN – Signal generators
    This chapter deals with analog and logic signal generators.
  7. REG – Function blocks for control
    The control function blocks form the most extensive sublibrary of the RexLib library. Blocks ranging from simple dynamic compensators to several modifications of PID (P, I, PI, PD a PID) controller and some advanced controllers are included. The blocks for control schemes switching and conversion of output signals for various types of actuators can be found in this sublibrary. The involved controllers include the PIDGS block, enabling online switching of parameter sets (the so-called gain scheduling), the PIDMA block with built-in moment autotuner, the PIDAT block with built in relay autotuner, the FLCU fuzzy controller or the PSMPC predictive controller, etc.
  8. LOGIC – Logic control
    This chapter describes blocks for combinational and sequential logic control including the simplest Boolean operations (not, and, or) and also more complex blocks like the sequential logic automat ATMT implementing the SFC standard (Sequential Function Charts, formerly Grafcet).
  9. ARC – Data archiving
    This sublibrary contains blocks for alarms generation and blocks for storing trend data directly on the target device.
  10. PARAM – Parameter handling
    This sublibrary contains blocks for parameter handling, namely saving, loading and remote manipulation with parameters.
  11. MODEL – Dynamic systems modeling
    The REXYGEN system can also be used for creating real-time mathematical models of dynamic systems. The function blocks of this sublibrary were developed for such cases.
  12. MATRIX – Working with matrix and vector data
    Function blocks for handling vector and matrix data in REXYGEN are includeed in this sublibrary.
  13. MC_SINGLE – Single-axis motion control
    Function blocks of this sublibrary were developed according to the PLCopen Motion Control standard for single axis motion control.
  14. MC_MULTI – Multi-axes motion control
    Function blocks of this sublibrary were developed according to the PLCopen Motion Control standard for motion control in multiple axes.
  15. MC_COORD – Coordinated motion control
    Function blocks of this sublibrary were developed according to the PLCopen Motion Control standard for coordinated motion control.
  16. SPEC – Special blocks
    The most interesting blocks of this sublibrary are the REXLANG and RDC blocks. It is possible to compile and interpret user algorithms using the REXLANG block, whose programming language is very similar to the C language (the syntax of the REXLANG commands is mostly the same as in the C language). The RDC block can be used for real-time communication between two REXYGEN-enabled target devices.

The individual chapters of this reference guide are not much interconnected, which means they can be read in almost any order or even only the necessary information for specific block can be read for understanding the function of that block. The electronic version of this manual (in the .pdf format) is well-suited for such case as it is equipped with hypertext bookmarks and contents, which makes the look-up of individual blocks very easy.

Despite of that it is recommended to read the following subchapter, which describes the conventions used for description of individual blocks in the rest of this manual.

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