Rockwell uses TI’s digital signal controller for ergonomics, safety

Milwaukee, WI; Houston, TX—To help improve industrial workplace ergonomics and safety, Rockwell Automation is using Texas Instruments’ TMS320LF2401A digital signal controller to bring digital signal processing (DSP) to operator interface applications

By Control Engineering Staff August 19, 2003

Milwaukee, WI; Houston, TX— To help improve industrial workplace ergonomics and safety, Rockwell Automation reported Aug. 12 that it’s using Texas Instruments ’ TMS320LF2401A digital signal controller to enable it to bring digital signal processing (DSP) to operator interface applications. Implemented initially in Rockwell’s Allen-Bradley Zero-Force Touch Buttons, TI’s LF2401A is only 7 x 7 millimeters, but processes 40 million instructions per second (MIPS). This makes it useful in space-constrained applications that need TI’s DSP technology and the control peripheral set and ease of use of a microcontroller (MCU).

Industrial operator interfaces increase safety by requiring users to activate pushbuttons that keep hands away from moving equipment. However, traditional pushbuttons require repetitive force to operate, and can lead to fatigue and strain related injuries. Rockwell’s Zero-Force Touch Buttons use independent, embedded sensors to convert an operator’s touch into an electrical output that initiates operation when hands or fingers are placed over the button. The buttons also use precise capacitive sensor timing, combined with a complex algorithm driven by LF2401A, to discriminate between a person’s touch and a foreign substance, such as clothing, fluid films or splashes, that could lead to accidental equipment operation.

‘We needed a processor that could handle this complex task and algorithm, as well as meet our strict size restrictions,’ says Rachael Karisny, Rockwell’s senior marketing engineer. ‘LF2401A was the only embedded processor that met these requirements, along with the price, service and support that we needed.’

LF2401A offers a five-channel, analog-to-digital converter (ADC) with a 500-nanosecond conversion time, which Rockwell says makes it ideal for applications requiring real-time processing, such as Rockwell’s Zero-Touch Buttons. The embedded controller also offers 8K of sectored, reprogrammable flash memory, which features encrypted security to protect intellectual code property. Even in the field, designers can now reprogram their products, and know their code and intellectual property are secure. The controller also has 1K words of on-chip random access memory (RAM), as well as read-only memory (ROM) for boot-up into flash memory. Additional peripherals include an event manager, a serial communications interface (SCI), a watchdog timer and 13 general-purpose input/output (GPIO) channels.

‘Embedded control designers now have an ultra small die equipped with the peripheral integration and ease of use of a microcontroller and the real-time processing performance of a DSP,’ says Todd Solak, TI’s C2000 worldwide marketing manager. ‘LF2401A is code compatible with the full line of C2000 controllers, which provide the broadest range of embedded control optimized solutions available.’

There are 17 digital signal controllers in the C2000 platform, which TI reports are designed for virtually all control applications. TI gives designers application-focused hardware and software tools designed to speed time to market, and a full array of complementary analog solutions designed to work with all C2000 controllers.

Control Engineering Daily News DeskJim Montague, news