Absolute MDrive

Multi-turn absolute encoder and control electronics integrated with stepper motors

Lexium MDrive® with multi-turn absolute encoder

Absolute MDrive® products integrate a 1000 line count (4000 counts/rev) multi-turn absolute encoder with 1.8° 2-phase stepper motor and control electronics. Rotary and linear motors are available. IP65-rated products for protection against dust and moisture are also available. These products can reduce machine complexity, size and cost for a wide variety of motion applications.

Robust Lexium MDrive (LMD) products are enhanced with a multi-turn absolute encoder at an extremely competitive price. Internal to the product so there is no increase in size, absolute encoders detect and store position information even when powered down. This can eliminate homing routines and reduce setup time at system startup.

At an extremely competitive price, multi-turn absolute encoders enhance LMD integrated motor and electronics products while fitting in the same compact footprint. OEMs who want to reduce machine size, cost and complexity will find robust Lexium MDrive with Absolute Encoder products deliver exceptional performance and value for many applications.

Frequently Asked Questions

What is the encoder resolution of Absolute MDrive?

The Absolute MDrive has the same encoder resolution as the existing closed-loop Lexium MDrive products, 1000 lines or 4000 counts/revolution.

Is the encoder resolution actually 4000 or 4096 counts/rev?

The resolution is actually 4000 counts/revolution. The analog input resolution for the Lexium MDrive is 4096, but the analog input is not available on the Absolute MDrive.

How many shaft rotations may occur before the multi-turn encoder loses position due to counter over-run?


To prevent rollover of Idx6062h (Position_demand_counter) an automatic rollback feature has been incorporated. When this counter reaches or exceeds 7/8 of the way (i.e. 70000000h=1,879,048,192), the counter is rolled back by that value. This is done to avoid confusing the internal micro-stepper state machine from interpreting a very positive number (i.e., >2^31) as a negative number and prevents the software routines from doing the same. Please note that a roll back feature is not available on the encoder itself. As a result, if Idx6064h (Position) is based on the encoder, Idx6064h (Actual) value will be offset from Idx6062h (Demand), and a following error will be set.

Motion Control, Ethernet TCP/IP

The encoder counter (C2) is a 32-bit register, meaning the shaft can rotate approximately +/- 41,000 revolutions before losing position.

How long will Absolute MDrives retain position information?

The unit will retain its position information for up to 30 days without the use of the optional ICP0531 External Battery Pack.

How many Absolute MDrives can the Battery Pack provide power to?

The optional ICP0531 External Battery Pack provides power to up to six (6) Absolute MDrives.

How long will the optional ICP0531 External Battery Pack allow Absolute MDrive position to be retained?

Using the optional ICP0531 External Battery Pack with six (6) Absolute MDrives connected, position will be retained for up to five (5) years. It is recommended that power be supplied to the Absolute MDrive for a minimum of twenty-four hours prior to changing batteries or disconnecting the optional ICP0531 External Battery Pack.

Are low level warning provisions available on the optional ICP0531 External Battery Pack?

  1. Yes, the optional ICP0531 External Battery Pack is equipped with a status LED. The LED will flash on every 10 seconds while the internal battery voltage is above the required threshold. If the status LED is not flashing, the internal battery voltage is not sufficient, and internal batteries will need to be replaced.
  2. The optional ICP0531 External Battery Pack is also equipped with a low battery signal output. The low battery signal output is essentially an open collector. When internal battery voltage is insufficient, the low battery signal output will provide 24 VDC. Internally, we utilize a 5.62K ohm resistor to pull up to 24 VDC. Current is based on the impedance of the input or load.

What are the environmental condition limits for the optional ICP0531 External Battery Pack?

The environment during transport and storage must be dry and free from dust. The maximum vibration and shock load must be within the specified limits for the Absolute MDrive.

Temperature (°C)-25 to 70
Temperature variation (°C)-25 to 30
Humidity (%)5 to 95 (non-condensing)

Note: Environmental conditions listed are only applicable to the ICP0531 External Battery Pack. Upon installation of batteries, manufacturer environmental condition limits for batteries must also be considered

What is the Absolute MDrive encoder communication protocol, SSI or EnDAT?

 The Absolute MDrive encoder utilizes communication technology proprietary to SEM USA. The absolute encoder does not utilize SSI or EnDAT communication protocols.

Can Programmable Motion or Ethernet TCP/IP Absolute MDrives provide position via encoder output signals?

Due to hardware restrictions, it is not possible for the Absolute MDrive to provide position information via encoder output signals. Position information is available by querying the encoder counter (PR C2 or fieldbus equivalent).


Lexium MDrive Products

Robust integrated motors, specially well suited for industrial applications

Built on the Lexium  MDrive  platform with the addition of external linear mechanicals

When it comes to your form, fit and function requirements, don’t settle. Get precisely what you need working with us. We know motion.

Contact us with any questions about how we can help you with your motion application or for assistance with your SEM products.

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