ISA Expo 2004: Micronor shows totally passive rotary encoder

Houston, TX—Micronor is exhibiting its patent-pending, incremental rotary encoder, MR312 ZapFree at ISA Expo 2004, Oct. 5-7, at the Reliant Center.

By Control Engineering Staff October 5, 2004

Houston, TX— Micronor is exhibiting its patent-pending, incremental rotary encoder, MR312 ZapFree at ISA Expo 2004 , Oct. 5-7, at the Reliant Center. The company report that MR312 is the world’s first commercially-available, entirely passive encoder for rotation sensing applications.

There are no integral electronics in the encoder housing and the all-optical design requires just one fiber-optic connection, which provides the most simplicity, reliability and ease of installation. Micronor adds that MR312 offers:

immunity to lightning and atmospheric static that would ‘zap’ conventional encoders;

outdistances copper cable by allowing link lengths to 1,000 meters (3,280 feet);

has an inert nature that’s ideal for use in hazardous and explosive environments; and

offers intrinsic EMI/RFI resistance that allows for safe and reliable operation in and around medical equipment and other ‘noisy’ industrial environments.

ZapFreepassivity, light weight, and the ability to transmit high data rates over extremely long distances.

However, MR312’s design goes one step further by using telecom-proven wavelength division multiplexing (WDM) technology that assigns each internal optical path to a wavelength, so that all wavelengths/paths can be combined onto one fiber. This method avoids using multiple fibers, which tends to increase optical harness costs. A single-fiber cable is inherently more cost effective than any multi-wire or multi-fiber or hybrid cable assembly, and is easier to handle and install as well.

Micronor offers its MR312 encoder and MR310 remote encoder interface (REI) as a turnkey solution with industry standard interfaces. MR312 is packaged in a standard Size 58 (58mm OD) encoder housing, and mechanically interfaces to motors and shafts, similar to conventional encoders. The optical connection between MR312 and MR310 REI is via one strand of industry-standard 62.5/125 multimode optical cabling. Downstream, MR310 converts the optical quadrature signals to both industry-standard open collector outputs (A, B) and line driver outputs (A, A’, B, B’) for connecting easily to a conventional counter, PLC, or computer interface board. The interface module is packaged in a standard 35-mm DIN rail mountable module, and draws a maximum 50 mA from a readily available 12-32 V dc power connection.

MR312 is an ideal match for applications exposed to lightning, atmospheric static, or plasma fields, such as those in aerial trams, ski lifts, wind turbine generators, radar/satellite antennas, and semiconductor plasma-etching equipment. It also provides safe use in petrochemical processing plants and other hazardous/explosive environments. Micronor says using its product ensures reliable machine operation in the presence of electrical noise, RFI, and other forms of interference found in and around industrial environments and heavy machinery, such as motors, brakes, clutches, smelters, and power transformers. For nuclear power plant and space applications, the simple design allows for ease of engineering radiation hardened and space compliant versions.

Besides its simplicity, MR312 can perform in a wide range of harsh environments. It can operate over a wide temperature range, from -40 °C to +80 °C, with an extended temperature option, which covers -60 °C to +150 °C. MR312 is initially offered in 100 ppr and 256 ppr configurations. While initially offered in a standard Size 58 package, MR312 can be easily upsized or downsized for specific applications.

Micronor supplies components for industrial automation and process control industries, as well as military, aerospace and other harsh environment applications. Its motion control products include encoders, resolvers, cam timers, programmable limit switches, motorized potentiometers, pulse generators and ergonomic pendant stations. Micronor was founded in 1968, and has regional headquarters in the U.S. and Europe.

Control Engineering Daily News DeskJim Montague, news editorjmontague@reedbusiness.com