What is an Absolute System?

Teach Me Please! Ms. Ori
Teach Me Please! Ms. Ori
  • Ms. Ori

    What's wrong with that difficult face, Vex?

  • Mr. Vex

    A customer told me that "they wanted to use Abso", so I'm doing some research, but I don't really understand the word Abso...

  • Ms. Ori

    I've heard that a lot lately. "Abso" is an abbreviation for "absolute system." The absolute system and the incremental system are often compared.

  • Mr. Vex

    Absolute system? Incremental system?

  • Ms. Ori

    It can’t be helped. The point of difference between the two is whether they retain position information when the power supply is off or not.

  • Mr. Vex

    When it comes to motor position information... It's the encoder right?

  • Ms. Ori

    Yes, the encoder. First, let's take a look at how the incremental system works. Take a look at the figure below.

    Incremental system
    Incremental system
  • Mr. Vex

    This means that when the power supply is ON, the encoder is supplied with electricity, so the position information can be retained, but when the power is OFF... the encoder is no longer supplied with electricity, so the position information is lost.

  • Ms. Ori

    That’s right. Next, let's take a look at the absolute system. See the diagram figure below to see how it works. Even when the driver power supply is turned OFF, the battery still supplies power, so position information can be retained.

    Absolute system
    Absolute system
  • Mr. Vex

    I see, but how should the customer use these two systems differently?

  • Ms. Ori

    Even if you know how it works, it's meaningless if you don't know what the benefits are for the customer. There is a table that briefly summarize the two systems, so take a look at the following table.

Advantages Disadvantage
Incremental System No battery To manage position information, return-to-home operation is required when power is turned on.
Absolute System Position information can be managed without a return-to-home operation Battery required
  • Mr. Vex

    The Absolute System remembers the position information even when power supply is OFF, so there is no need for return-to-home operation.
    That means... You can turn on the equipment and get it running right away.

  • Ms. Ori

    Yes, it will reduce takt time. Also, there are cases that the return-to-home operation is no longer needed, eliminating the need of home sensor and limit sensor.

  • Mr. Vex

    No need of sensors means lower costs and less wiring!

  • Ms. Ori

    Just be careful when using batteries. Batteries have a limited lifetime and need a regular maintenance, which adds cost and time for replacement. If you remove the battery, power will no longer be supplied to the encoder and position information will be lost. You may also need to adjust the home again when you disconnect the motor and the driver.

  • Mr. Vex

    I see. Now that I understand how the incremental system and the absolute system work and how they are used.

  • Ms. Ori

    Good to know. So, now that you understand the absolute system, I'll give you some additional information Vex. Do you know the AZ Series stepper motors equipped with battery-free absolute encoders?

  • Mr. Vex

    It’s an absolute system, but no battery required?

  • Ms. Ori

    The AZ Series has a newly developed ABZO Sensor * behind the motor, able to manage position information even without a battery.

    • *ABZO sensor: Mechanical multi-rotation absolute encoder
    AZ Series
    Battery-free absolute system AZ Series
  • Mr. Vex

    What!! That's amazing. In that case, there would be no need to replace the battery, and there would be no need to adjust the home position even if the control cabinet and mechanism were carried separately. I'll introduce to my customer as soon as possible! The AZ Series is so clever.

  • Ms. Ori

    Vex, even if I'm not around, please keep track of the product information.

  • Mr. Vex

    Yes…! I'll do my best, following the AZ Series’ example!

Related Products