What is the difference between a single-turn and multi-turn absolute encoder in terms of power-loss position retention?
There is a key difference between single-turn and multi-turn absolute encoders, particularly in power-loss position retention. Here are the differences listed:
Single-Turn Absolute Encoder
- Generating innovative and unique code for each angular position within a full 360° rotation
- Information is being directly encoded on a physical disc
- Information is retained without any power or memory loss in the component
- The controller archives the exact angular reading
To learn more, you can also check out (Understanding Single-Turn Absolute Encoders: Performance, Integration, & Maintenance) for nuanced details.
Multi-turn Absolute Encoder
- Extends through the simultaneous capture of total shaft revolutions, besides the precise angle on each turn
- Correct choice for the lead screws along with robotic arms, conveyor systems and valve actuators
- The shaft travels through many simultaneous rotations and a cumulative travel distance.
- Preserving the revolution count through the gear-cascade mechanics
At Briter Encoder, our absolute encoders provide a numeric value for either singleturn or multi-turn shaft revolutions.
Why does an absolute encoder not need homing or recalibration after power is restored, unlike an incremental encoder?
The incremental encoder does not have a built-in sense of position. It only measures motion relative to a starting reference point, and thus, once power is lost, the reference is entirely gone. Therefore, before the machine can operate safely, it must perform a full homing process, which is time-consuming, affects the mechanical parts, and reduces the machine’s productive uptime in every homing cycle.
An absolute shaft encoder functions quite differently. Since each position corresponds to a unique value in the disk-coding pattern, when the power comes on, the industrial position encoder provides an immediate, precise position reading. The shaft will not need to be moved. Technicians are not required. No cycles are run to calibrate.
Wrapping Up
The loss of power does not specify positional uncertainty. Whether you need precise angular feedback with the absolute shaft encoder or the absolute hybrid shaft encoder, the best multiturn absolute encoder for position tracking with thousands of revolutions, you can’t miss that the absolute shaft encoder gives your system the precise information you need, the first time you turn it on.
Looking to implement homing delay elimination and gain protection from power-loss errors for your process? Make the most of Briter Encoder’s full selection of absolute encoders while talking to one of our specialists via email brt@briterencoder.com! Shop Now. Designed for the most demanding industrial environments, Briter Encoder offers an extensive lineup of absolute rotary encoders, including integrated waterproof (IP68) and miniature versions, as well as explosion-proof models.
FAQs
- Can a power failure permanently erase an absolute encoder’s position data?
No, in the single-turn models, there is no data on the disc that can ever be lost, no matter what happens to the power supply. For models built over multiple turns (EEPROM or Wiegand energy harvesting), revolution data is safely written before power is lost. - Are absolute encoders suitable for wet or hazardous environments?
Yes. Enhanced waterproof absolute encoders are rated dustproof to IP68, which means water will never enter the device. - Which communication protocol should I choose for my absolute encoder application?
The correct protocol will be dependent on the control system architecture and cable run distances. Our absolute encoder range can communicate with RS485, Modbus RTU, RS232, RS422, CANbus, CANopen, SSI, BiSS-C, SPI, TTL, and analog output signals (0-5V, 0-10V, 4-20mA). RS232 or RS485/422/423 are usually used for long-distance industrial networks, depending on the required speed. For high-speed/ high-precision servo applications, the standard is SSI or BiSS-C.
