An absolute optical rotary encoder from Baumer Electric Ltd., Southington, Conn. (www.baumerelectric.com), features 36-bit resolution and measures 262,144 pulses/rev over 262,144 revolutions. That means the encoder can track over 68 billion pulses with unique binary codes. The device is compact, measuring 55 mm deep and 58 mm in diameter and weighs 370 gm. Six input lines supply power and allow readout, programming functions, and parameter assignments. The encoder also uses fewer radially arranged code tracks, yet provides better resolution and uses a smaller pulse disc. It also lets the 18-bit use only two code tracks.

Internal electronics reduce output lag, letting the device accurately monitor rotary process spinning at up to 6,000 rpm. It supports most major bus systems, including SSI, CANopen, DeviceNet, and Profibus, as well as RS-485 outputs. It features 50-g shock protections and IP 64 sealing, and will operate at temperatures from -20 to 85*C.