Absolute Position Sensors

Elmo drives work with protocols from a wide range of absolute position sensors. During operation, absolute position data is read continuously from the encoder.

Up to 32 bits of sensor position data can be read. In rotary sensors, up to 30 bits can be read per revolution. When a sensor provides more than 32 bits of position data, the user can choose to mask low and/or high bits as required.

Currently, Elmo supports the following sensor protocols:

• Synchronous Serial Interface (SSI) open protocol developed by Max Stegmann GmbH. This generic protocol enables each vendor to implement different features and data message structures. Elmo’s implementation supports:
  • Programmable clock frequency
  • Binary or gray code
  • Error bit
  • First clock delay
• Panasonic® protocol, a propriety protocol with a fixed 2.5 MHz clock frequency. Elmo drives support:
  • 17 bits single turn sensor
  • 17 bits single turn plus 16 bits multi-turn sensors

Elmo supports error detection and CRC error detection.

• Tamagawa® protocol, a propriety protocol with a fixed 2.5 MHz clock frequency. Elmo drives support:
  • 17 bits single turn sensor
  • 17 bits single turn plus 16 bits multi-turn sensors

Elmo supports error detection and CRC error detection.

• • Bi-directional Synchronous Serial Interface (BiSS) open protocol, developed by iC-Haus. Elmo supports both B-Mode and C-Mode as well as BiSS data mode. Elmo’s implementation fully supports the Renishaw BiSS sensor, as well as a generic BiSS implementation which includes:
• • 6 bit CRC (X6+X1+X0)
  • A single error bit active low or active high
  • Non-binary resolution
• • EnDat® 2.2 protocol, a propriety protocol by Heidenhain. Elmo supports all known resolutions both in linear and rotary sensors. For sensors with resolutions higher than 32 bits, masking of high and/or low data bits enables reading of only 32 bits of position data. Elmo supports:
• • • CRC error detection
    • Operating status error messages, and
    • Start bit (enabling automatic propagation delay)

Design Features

• Programmable clock frequency, up to 2.5 MHz
• Input glitch filtering for improved noise immunity
• Counting direction inversion
• Masking of low and/or high position data bits
• Automatic propagation delay compensation

For more information please contact our motion control experts.

For more information please contact our motion control experts.