Each CPU module is equipped with two Ethernet ports for communication with other controllers and for interaction with operators, engineers, managers, and higher level applications. A Compact Flash memory card can be inserted into a slot in the CPU module to store the application and data.
The connectivity and expansion options make the AC 800M exceptionally open and scalable, that is, easy to connect to the surrounding world of supervisory systems and intelligent devices of all kinds - and adaptable to changing requirements as the process it controls changes or expands.
AC 800M High Integrity Controller
The AC 800M High-Integrity offers an IEC 61508 and TÜV-certified control environment for combining safety and business critical process control in one controller unit without sacrificing the safety integrity.
AC 800M Engineering
AC 800M control applications can be created in any of the five IEC 61131-3 dialects by using Engineering workstation, and then be downloaded to controllers using the Control Builder. Control applications can be distributed and executed on several controllers and communicate with each other on Control Network using named variable communication. Parts of the application can be downloaded to ifferent controllers.
The functionality range for control applications is wide, from binary control to closed loop control, with advanced functions like auto tuning PIDs, fuzzy control, etc. Pre-defined process objects like motor objects, valve objects, etc. are available.
It is possible to build user-defined function blocks, and also to hide its content in order to protect the intellectual property. User-defined serial protocols can be developed in structured text with the support of special functions needed, e.g. for checksum calculation.
Control Modules extend the IEC 61131-3 language to an object-oriented configuration method. The Control Module concept raises the abstraction level of engineering by hiding details in pre-defined control blocks. This enables reuse to a higher degree, making repetitive engineering very efficient.
Function Block Diagram
Function Block is a graphical language for depicting signal and data flows by means of library-stored software elements and interconnecting signals. Function block programs are easy to develop and, thanks to the resulting graphical diagrams, also easy to read.
Structured text (ST) is a high-level programming language. It has a comprehensive range of constructs for assignments, function calls, expressions, conditional statements, iterations, etc. ST lends itself well to writing advanced, compact - yet easily understandable - programs thanks to its logical and structured layout.
Ladder diagram (LD) is a graphical language based on relay ladder logic. Hence it is suitable for those who prefer to define interlocks and control actions in terms of relay contacts and coils, and other functions as "black boxes".
Sequential Function Chart
Sequential function chart (SFC) is a graphical language for depicting the sequential behavior of a control system. It is used for defining time- and event-driven control sequences. A sequence is shown in flow-chart form, using steps, transitions and selection nodes. The language is amply suited to the handling of control tasks which are sequential in nature, i.e. consisting of a number of distinct steps, each requiring a number of enabling inputs where the completion of the previous step usually is one of them.
Instruction list (IL) is a low-level, execution-efficient PLC language where each statement corresponds to a single or only a few processor instructions. It has a structure similar to Assembler.
Changes can be made to a running application without loss of data. There is no limit to the size and number of changes that can be made. Security features are built in to prevent unintentional downloads.
Configuration and Downloading
Applications can either be loaded into the target controller(s) by non-volatile Compact Flash memory cards or over a serial link or Ethernet network into battery backed-up RAM. The former approach is suitable for smaller and more standardized duties where users can be spared involvement in the application software development and handling process. The latter is intended for larger and more unique applications where debugging and improvements can be expected to become recurring engineering tasks.