IEEE 1621

IEEE 1621 ("Standard for User Interface Elements in Power Control of Electronic Devices Employed in Office/Consumer Environments") is a standard published by the IEEE and approved by ANSI that describes human interface guidelines regarding power controls in consumer electronics. It includes terminology, icons, and lighting. IEEE 1621 references the following standards: ANSI/VITA 40, CIE 107, IEC 60073, IEC 60417, IEC 60447, IEC 62301, IEC 80416-1, IEC 80416-3, ISO 7000, ISO 9186, ISO 9241-1, ISO 9241-10, and ISO/IEC 13251.

History and Motivation

Standardization of power controls in consumer electronics was spearheaded by Bruce Nordman at Lawrence Berkeley National Laboratory with funding provided by the California Energy Commission Public Interest Energy Research Program. Nordman's research showed that many computers had power saving features disabled, mainly due to consumer confusion due to the lack of standardization of terminology and symbols in both hardware and software. Confusion was further compounded due the symbol IEC 60417-5009 (⏻) meaning that the device was only in a low power state, rather than being disconnected from a power supply. Per IEC 60417-5009 this is defined as "stand-by." This allows for ambiguity. For example it could mean that the device is entirely off aside from an illuminated "off" indicator or in a sleep mode.

In April, 1998 the project was submitted to the California Energy Commission with the project starting in June of 2000.

The IEEE New Standards Committee approved working group 1621 to develop a power controls standard in September of 2002. Three months later a draft of IEEE 1621 was published.

The final standard was approved by the American National Standards Institute on 2005-03-24 and the standard was published on 2005-06-08.

Standards

Definitions on power states
Power state Definition
Disconnected Off power state with no power supply.
Hard-off Off power state with no power draw from mains or battery.
Off A power state with less than or equal power draw and similar functionality compared sleep or on.
On A power state with greater than or equal power draw and similar functionality compared sleep or off.
Sleep A power state with less than or equal power draw to on and greater than or equal to off.
Soft-off Off power state with possibility of power draw from mains or battery or not.
Transition Limited user-perceptible duration of switching power states.
  The basic standard power levels as defined in IEEE 1621. All other power levels are variants based off of these 3.

Power state formulas:

PON≥PSLEEP

PSLEEP≥POFF

PLIGHT SLEEP≥PDEEP SLEEP

Power state indications
State Indicators light colors Symbol
Power Sleep
On Green Off
Sleep Yellow Yellow
Off Off Off
Error Red Off
Green (alternating with yellow or with sleep's indicator light) Yellow (alternating with power's indicator light)
Power symbols
Symbol Name Usage
 On For a switch.
 Off For a switch.
⏼
 On/Off On a switch that always switches off to a hard-off state.
⏻
 Power On a switch where it either can variability switch to a soft-off or a hard-off state.
 Sleep For a sleep button or indicator.

Regulation

Energy Star encourages the use of IEEE 1621.

EU Commission Decision 2009/347/EC encourages the use of IEEE 1621.

EU Commission Decision 2016/1756 encourages the use of IEEE P1621.

See also

Notes

  1. ↑ This equation is only for guidance for other power states.
  2. ↑ This scheme shall not be used to indicate a safety hazard.
  3. ↑ This scheme shall not be used to indicate a safety hazard.

References

  1. ↑ "IEEE Std 1621-2004 - IEEE Standard for User Interface Elements in Power Control of Electronic Devices Employed in Office/Consumer Environments". webstore.ansi.org. Retrieved 2026-10-24.
  2. 1 2 "IEEE Standards Association". IEEE Standards Association. Retrieved 2026-10-24.
  3. ↑ "WIMS> Power management standards links". beta.pwg.org. Retrieved 2026-10-26.
  4. ↑ "Know What The Power Button Symbol Says". www.instantfundas.com. Retrieved 2026-10-26.
  5. ↑ Team, Origin Trace Editorial (2026-07-05). "The History of the Power Symbol: The International Standard Behind I, O, and ⏻". Origin Trace. Retrieved 2026-10-26.
  6. ↑ dankrotz (2003-06-16). "Simple Symbols that Save Energy - Berkeley Lab". Berkeley Lab News Center. Retrieved 2026-10-26.
  7. ↑ "Read The Proposal – Unicode Power Symbol". Retrieved 2026-10-26.
  8. ↑ IEEE Standard for User Interface Elements in Power Control of Electronic Devices Employed in Office/Consumer Environments, IEEE, doi:10.1109/IEEESTD.2005.96205, ISBN 978-0-7381-4650-8, retrieved 2026-10-24
    1. ↑ "2. Normative references". pp. 1–2.
    2. ↑ "3. Definitions and special terms". p. 3.
    3. ↑ "4. Power controls for electronic devices". pp. 4–5.
    4. 1 2 "4. Power controls for electronic devices". p. 4.
    5. ↑ "4. Power controls for electronic devices". p. 5.
    6. ↑ "4. Power controls for electronic devices". p. 7.
    7. ↑ "4. Power controls for electronic devices". p. 8.
    8. ↑ "4. Power controls for electronic devices". p. 6.
  9. ↑ "Power Management Controls - Contact Us". ea-controls.lbl.gov. Retrieved 2026-10-24.
  10. ↑ Nordman, Bruce (2005-05-02). "Power Control Made Easy". EE Product News. Archived from the original on February 16, 2009. Retrieved 2007-04-26.
  11. ↑ "winhec02.pdf" (PDF). Archived from the original (PDF) on 2004-11-01.
  12. ↑ "IEC 60417-5009:2015". products.iec.ch. Retrieved 2026-10-24.
  13. ↑ "IEC 60417 – 5009, Stand-by". IEC.
  14. ↑ "Power Management Controls - News". ea-controls.lbl.gov. Retrieved 2026-10-24.
  15. ↑ "Power Management Controls - User Interface Standard - IEEE 1621". ea-controls.lbl.gov. Retrieved 2026-10-24.
  16. ↑ "ENERGY STAR® Program Requirements for Televisions" (PDF).
  17. ↑ "Commission Decision of 20 April 2009 determining the Community position for a decision of the management entities under the Agreement between the Government of the United States of America and the European Community on the coordination of energy-efficiency labelling programmes for office equipment on the revision of the imaging equipment specifications in Annex C, part VII, to the Agreement (2009/347/EC)". legislation.gov.uk.{{cite web}}: CS1 maint: url-status (link)
  18. ↑ "Commission Decision (EU) 2016/1756". Official Journal of the European Union: 12. 28 September 2016.