IXARC absolute encoders by POSITAL now available with SSI interfaces

The new generation of IXARC encoders from POSITAL is now available with SSI communications interfaces.

POSITAL-Fraba manufactures the IXARC line of magnetic absolute rotary encoders, and the next generation of these devices is available with SSI (Synchronous Serial Interface) communications interfaces. SSI is a commonly used communications protocol for absolute encoders and many other kinds of sensors, supported by most major PLC manufacturers on the market.

Part of the POSITAL NEXTGEN program, these IXARC encoders also feature advanced Tunneling Magnetic Resistance (TMR) sensors for single-turn angular position measurement.

No backup batteries needed

A serial communications system, SSI connects sensors directly to digital PLCs or microcontrollers through point-to-point wiring systems based on RS-422 communications standards. This results in high transmission rates and can support connections over distances as far as 1,200 metres. The maximum baud rate depends on the transmission distance. POSITAL encoders with SSI interfaces are programmable, so users can configure resolution, direction of rotation, code, and preset via simple software updates with the convenient POSITAL UBIFAST programming tool.

A key advantage of using TMR sensors is that they are more stable, less temperature-sensitive, and more responsive to small changes in the magnetic field than the Hall effect sensors they are replacing in these encoders. This paves the way for a higher resolution of up to 18 bit. Another major innovation in this next generation of IXARC encoders: a new ASIC, designed in-house to support battery-free rotation counting in multi-turn variants. Whenever the encoder shaft completes a rotation, a Wiegand sensor connected to the ASIC provides both a signal pulse and sufficient electrical current to energize the counter circuitry in the ASIC. Every shaft rotation is recorded accurately in non-volatile memory through this self-powered counter system, even if the rotation occurs when the system power is unavailable, so no backup batteries are needed.

The POSITAL team has refined the housings in these new IXARC encoders, with compact new models available. Among the other options are variants with interface connections that are angled at 45 degrees to the shaft axis; this serves as an alternative to axial or radial connectors and can make installation of these solutions in confined spaces simpler.

For more information, contact POSITAL.

• Tweet