PLC doubles as network controller
Monday, 27 October 2008The new Controller-E from ifm efector, Exton, Pa. (www.ifmefector.com), is a high-speed AS-I master and PLC integrated into a compact housing. It features 1 Mbyte of total memory and can be used as a stand-alone controller or as a gateway to higher-level bus systems. As a gateway, the Controller-E can connect two full AS-I systems, up to 868 I/O points, as one node on a higher-level bus system. Information passes transparently from the AS-I system to the higher network without the need for additional software, and a full-range of diagnostics are available to both systems. Interfaces include Profibus, DeviceNet, and Ethernet (Modbus TCP/IP and Web enabled). The Controller-E fully supports all AS-I 2.1 extensions, including the extended-addressing mode that allows up to 62 nodes on each master. The master also supports peripheral fault indication and connects analog devices without function blocks As a PLC, the 128-K word program memory holds more than 300 counters and timers. The software conforms to the IEC61131-3 standard supporting five programming languages: Ladder, Function Block Diagram, Sequential Function Chart, Structured Text, and Instruction List. It also supports standard PLC functions such as floating-point math, real-time clocks, and online changing. The unit features a highly visible four-line LCD display that lets users instantly check operational status or diagnostic information. Data include status of digital I/Os, analog values, fault messages, freely programmable texts, and user-defined messages. In many applications this eliminates the need and expense of a separate MMI unit. Pushbutton programming and a configurable menu structure provide quick setup, and the integrated display can be changed from English to another language, such as German or French. According to the company, the dual-function device is ideal for distributed-control systems because it can reduce plant downtime, shorten machine cycle times, and simplify programming and maintenance. Four Controller-E models are available in single and dual models that range from $715 to $1,160.