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Four new CPUs with more power and more functions
Siemens Automation and Drives (A&D) will unveil at this year's Hanover Fair a new family of particularly powerful CPUs for its Simatic-S7 300 controllers. The new 317 series CPUs are available in four versions for a wide variety of applications. The new line includes the standard CPU 317-2 DP, the technology CPU 317T-2 DP with motion control functions and high-speed I/O for motion control tasks, the CPU 317-2 PN/DP with Ethernet/Profinet interface for Component based Automation, and the fail-safe CPU 317F-2 DP for safety-related applications. The new high-end CPUs enable high machine cycle rates for faster throughput. They are particularly well suited for factory automation, for example special and series machine construction and plant construction.
The new CPU family excels in the areas of program execution and communication, one example being an instruction execution time of less than 0.1 microseconds for word operations and less than 5 microseconds for floating-point arithmetic. With 512 kilobytes of RAM, the CPU is also adequately dimensioned for graphical programming languages. "Sequencers" in S7-Graph or "state graphs" in S7-HiGraph allow users to program their automation solutions quickly and easily. All new CPUs provide a wide variety of integrated functions. For example, they can maintain as many as 32 simultaneously active communication links to other automation equipment such as PCs, Operator Panels or programming devices.
The standard CPU 317-2 DP, which will be available in July 2003, is equipped with a Profibus-DP interface and a combination DP/MPI interface, both of which can be configured as Profibus master or Profibus slave. The start of delivery for the other 317-series CPUs, all of which are based on the standard CPU, is planned for September 2003, the delivery begin for the Ethernet-/Profinet CPU for December 2003.
The CPU 317F-2 DP is designed specially for use in fail-safe applications, and is conformant with the important IEC 61508 (SIL 3), EN 954 (Kategorie 4) and NFPA 79 specifications and standards. The fail-safe programs are written in the Step 7 ladder diagram (LAD) and control system flowchart (CSF) languages and supplemented by pretested, certified "Distributed Safety" function blocks, making it possible to use the same Simatic tools and languages for the engineering of both the standard and fail-safe sections. The CPU enables parallel operation of standard and fail-safe program; Profibus with Profisafe protocol is used for communication.
The Ethernet CPU 317-2 PN/DP offers a combination Profibus-DP/MPI interface as well as a 100 megabit/s Industrial Ethernet interface based on the Profinet communication standard, making it suitable as network interface between Ethernet and Profibus. The Profinet communication functions – PN in the module identification stands for Profinet – are used for Component based Automation in the modular plant and machine construction industries. The Profinet and S7 protocols communicate via Ethernet TCP/IP, and the CPU is also programmed in Step 7 over Ethernet.
The technology CPU 317T-2 DP is equipped with powerful technology and motion control functions as well as with local digital I/O modules and two Profibus interfaces. The four digital inputs and eight digital outputs are capable of processing high-speed signals from the process and outputting cam signals. For dynamic motion control of multiple coupled or individual axes, the drives are coupled in isochrone mode over the equidistant Profibus. The axes are configured, limit values and monitors set, and the drives initialized, put into operation and diagnosed using Step 7. The motion control functions are integrated in the standard Simatic languages and are based on the PLCopen Standard for motion control. Additional motion control software is thus unnecessary. Pretested technology functions are "controlled positioning" in "absolute', "relative", "additive" and "superimposed“; "traverse to fixed limit stop"; "gear and curve synchronism"; "print-mark compensation via probe"; and "path-dependent or time-dependent cam switching".
Additional information will be available at the beginning of April (in time for the Hanover Fair) on the Internet at: www.siemens.com/simatic-controller









