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Soft Motion / Real-Time Technology

Q: What is soft motion?

A: Soft motion is real-time motion control software: a PC-based motion control in which a single PC performs all real-time motion control operations including feedback loops and multi-axis coordination, and the servo loops are entirely closed in the CPU.

Soft CNC is a type of soft motion that includes industry-standard CNC functions and features, such as G code processing, NC path generation and a traditional CNC graphical user interface.


Q: What is soft PLC?

A: Soft PLC is real-time PLC software: a PC-based programmable logic controller in which a single PC monitors and controls the machine or machine tool based on inputs and outputs. Soft PLC runs on the same PC as the soft motion control, and is tightly integrated with soft motion to provide a single motion/machine control application.


Q: How different is soft CNC from conventional PC-based NC?

A: In conventional PC-based NC, the PC is used only as the operator's interface and expensive motion control boards are actually used for motion control processing. With Soft Servo Systems' soft CNC, the personal computer is used for all real-time motion control operations including feedback loops and multi-axis coordination. It also serves as a user-friendly graphical interface, can be connected to a network, used to store motion programs, and run other applications like database software, spreadsheet programs, vision systems or statistical process control applications.

For example, many competing CNCs operate on the arithmetic unit of a microprocessor on a special motion control board. The only difference with Soft Servo Systems' software is that it operates on the arithmetic unit of the CPU of a personal computer, because the CPUs of PCs are such high speed today.


Q: What are the advantages of soft motion over conventional PC-based controls?

A: Soft Servo Systems' technology is less expensive because it eliminates costly plug-in motion control boards and reduces complex wiring and hardware requirements, such as high-priced encoder-specific or servo-specific interface modules, analog and encoder cables from the PC, etc.

With Soft Servo Systems' open architecture, products can be easily customized or extended (developing specialty G codes, for instance), and integrated with other Windows-based software. System setup and integration is simplified, and Soft Servo Systems' products are scalable and flexible.


Q: How is real-time performance guaranteed when Windows operating sytems do not provide real-time processing?

A: Soft Servo Systems' products use an industry-proven real-time extension to Windows operating systems to create a real-time subspace (RTSS). In the RTSS, the Motion Engine and the PLC Engine are given first priority by the CPU. This means Soft Servo Systems' software monopolizes the CPU and runs in the RTSS. Any remaining CPU time is offered to Windows, which can then run any Windows applications. Soft Servo Systems' software is not running on Windows, but running under Windows, and Windows runs on Soft Servo Systems software. Soft Servo Systems' products are not Windows applications.


Q: How reliable is a commercial PC?

A: In general, commercial PCs are tremendously reliable, and their reliability is constantly improving. However, because the personal computer is provided by and can be freely chosen by the customer, the reliability of the PC becomes the customer's responsibility.


Q: What kind of performance can I get?

A: Soft Servo Systems' soft motion technology fully exploits the super-fast, super-precise (double-precision floating point) computation power of today's ordinary PCs – computation power which, until recently, was available only with a supercomputer. Soft Servo Systems' products harness the ever-improving CPUs in computers: as the speed and power of CPUs increases, so does the speed and power of a Soft Servo Systems motion control or CNC system.


Q: How reliable is the real-time operating system?

A: Soft Servo Systems has used the same real-time extension to Windows operating systems since the company was founded, and has found it to be more than suited for the demanding applications of general motion control and CNC.


Q: If multiple demanding applications are run on a Windows operating system as well as a Soft Servo Systems motion control or CNC product, does the computer operate normally?

A: Yes. However, depending upon the CPU's processing speed, the amount of RAM, and the number of programs running, the user may experience their computer as running slowly. But problems of this sort would be similar to running demanding applications on a Windows computer without a Soft Servo Systems motion control or CNC product.


Soft Servo Systems, Inc.