Calculating the phase-shift between the transmitted and reflected light beams provides distance measurements with millimeter precision.
For long-distance position feedback and data communications, the LE-100 optical measuring system and data transmission devices OD-500 and OD-2M offer encoder and trailing control cable alternatives.
As a substitute for traditional encoders, line potentiometers, and rotary transducers, the optical measuring system uses a visible red laser beam (wavelength 670 nm) in a clear line of sight to measure distance between itself and a moving reflector. The principle of phase shift measurement enables calculation of measured values, with very high reproducibility, within a few millisec, at speeds of up to 5 m/sec. Interfaces include SSI, Interbus-S, Profibus-DP, and CAN.
Advantages include short integration time, absolute measurement value with no reference procedure, openly configurable resolution, and reproducibility of ±2 mm. Due to the optical range-finder technique, no slip or wear develops during linear movement conversion, as can occur with rotary transducers.
The optical data communication system was designed to replace trailing remote control cables for serial data transfer. With data rates up to 500 kbits/sec, the OD-500 is suitable for Interbus-S, Profibus-DP, and Profibus FMS data. OD-2M provides data transmission rates up to 2 Mbits/sec.
Dan Reese,TR Controls Inc., Box 2543, Station "B", London, Ontario, Canada N6A 4G9; Tel: (800) 265-9483; Fax: (519) 452-1177; E-mail: email@example.com.