Rockwell Automation 842E EtherNet/IP Absolute Encoder User Manual - Manual (Page 12)

4 Rockwell Automation Publication XXXX-X.X.X - Month Year
Chapter 2 Encoder overview
Multi-turn units assign a unique digital output for each shaft position across
multiple shaft rotations and are capable of extremely high resolutions. Rockwell
Automation absolute encoders are available with an enclosure rating of NEMA
Type 4 and IP66, as well as a variety of mounting options. Applications include
steel mills, overhead cranes, punch presses, transfer lines, oil rigs, wind mills,
machine tools, and packaging.
Sine-cosine
A sine-cosine encoder is a position transducer using two sensors, each 90° out of
phase with respect to the other. Sine-cosine encoders can be used directly by the
drive or squared to provide a conventional A quad B digital signal. Therefore, the
sine-cosine encoder can be used as an absolute, sine-cosine, or incremental
feedback device.
Single-turn vs. multi-turn
Absolute encoders are either single-turn or multi-turn. Single-turn encoders are
used if the absolute position of the shaft for one revolution is required. Multi-
turn encoders are used if the absolute position is required for more than one shaft
revolution.
842E encoder features The 842E EtherNet/IP encoder features include:
• Support for the encoder profile 22h (0x22) defined in the Common
Industrial Protocol (CIP
™
), according to IEC 61784-1
• Compatibility with star, linear and device level ring topology
• Robust nickel code disk for harsh ambient conditions
• Configurable resolution per revolution: 1 to 262,144
• High precision and availability
• Ball bearing spacing of 30 mm for longer life
• Face mount flange and servo flange/blind hollow shaft and through
hollow shaft
• 18-bit single turn resolution
• 30-bit total resolution multi-turn resolution