What is Virtual Encoder and how does it work? I found this phrase in swing gate operator Brochure
(FAAC s418)datasheet. It says above "New control board with anti-crushing system and virtual encoder for inversion on obstacles".
( but not in datasheet)

  • \$\begingroup\$ Marketing talk by the sound of it. \$\endgroup\$ – Andy aka Sep 21 '16 at 17:11
  • \$\begingroup\$ I can't find the word "virtual" in that datasheet. Plenty of references to real encoders though. \$\endgroup\$ – Transistor Sep 21 '16 at 17:20

It actually does not sense obstacles , so "virtual encoder"

But it can predict normal motor current which rises from friction or blocking object or human so it does not crush the victim.

"inversion on obstacles" is obfuscated marketing lingo for " reverse gate motor direction"

Garage door open/closers work the same way by sensing motor current.

p.s. the manual was written by an engineer with tech writer support

  • the advertisement was written by a non-technically minded salesman

"Test the gate operator monthly. The gate MUST reverse on contact with a rigid object or when an object activates a non-contact sensor. If necessary, adjust the force or the limit of travel and then retest the gate operator. Failure to properly adjust and retest the gate operator can increase the risk of injury or death."

@transistor is correct that lots of encoders are listed in datasheet, but little clue as how they work "The obstacle detection function is achieved by controlling the current absorption and / or through the encoder connected to the motors." p25

  • ENCODER on motor 1 or motor 2 error

    appears to be a rotary encoder to measure sudden slight change in speed with high power hydraulics and other protective circuits.

    • 2EASY interface terminals

      is a wire loop (RF method) of sensing proximity of a car steel for auto open, so presumably buried in asphalt/concrete for auto sentry opener on exit.


It's marketing speak, as @AndyAka wrote. The datasheet reveals that there's a "2easy" bus connection to which you can connect various safety-related accessories e.g. extra photocells or switches.

I suspect that the "2easy" bus is in reality an AS-i digital industrial serial bus. The bus isn't limited to data, but can carry power to a wide variety of sensors.

After some searching I found this, indicating that the "Virtual encoder" is a proprietary serial interface absolute rotary encoder.

Another possibility is that "virtual encoder" really means just obstacle detection via current sensing, as @TonyStewart wrote in his answer. The datasheet states that encoder connectivity is only available with some actuator models, so I suspect that absolute encoders can be attached but not necessarily to your specific product.


"Virtual Encoder" (yes it is there in the top bullet-list of "features") means that the gadget "estimates" its position by how many steps the motor has been commanded, and assuming that the motor has actually moved. That is why there are so many warnings about using EXTERNAL sensors, etc.

It is marketing-speak for "we made this cheap by not including a real encoder, so beware about crushing your visitors to death."

It makes an attempt of sensing an obstacle by monitoring the motor current. But that is not the same as actually using a proper sensor to detect obstruction or obstacle.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.