Functional block · MMSS

Microgrid measurement stale-data supervisor

Functional block · Microgrids

An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.

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In plain English

What this block does

Marks the assigned power-system measurement invalid when its defined freshness condition is exceeded.

A simple example

In a microgrid control room, the operator can see source availability, active constraints and current operating mode. A communication failure should remain distinguishable from an electrical resource failure. For this reference, the drawing identifies “Measurement age and quality” at the input and “Stale-data indication” at the output. The permitted age depends on the control use.

Measurement age and qualityMMSSStale-data indication
A reading guide. The entry's original illustration and input/output facts describe this application.

What the drawings help you do

Start at the named input: Measurement age and quality. Identify its source device or document and the state represented on the drawing. Follow the named output: Stale-data indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Measurement age and quality
Output
Stale-data indication
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: Microgrid control systems

Schematic · MMSSMicrogrid measurement stale-data supervisor: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Marks the assigned power-system measurement invalid when its defined freshness condition is exceeded. Microgrid supervision coordinates measurements, control authority and resource communication without replacing local protection. Each resource value needs a named measurement boundary, freshness condition and intended control use.

In a microgrid control room, the operator can see source availability, active constraints and current operating mode. A communication failure should remain distinguishable from an electrical resource failure. For this reference, the drawing identifies “Measurement age and quality” at the input and “Stale-data indication” at the output. The permitted age depends on the control use.

Identify signal ownership, quality flags, control priority and loss-of-data behavior. These functional references do not certify cyber security, closed-loop performance or equipment interoperability. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.

How to read it

  • Start at the named input: Measurement age and quality. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Stale-data indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • The permitted age depends on the control use.
  • Identify signal ownership, quality flags, control priority and loss-of-data behavior. These functional references do not certify cyber security, closed-loop performance or equipment interoperability.

Information to show or reference

  • Label the source and connection reference for measurement age and quality.
  • Identify the destination and defined state of stale-data indication.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: The permitted age depends on the control use.

A distinction that matters

The permitted age depends on the control use. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Sources you can follow

These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.

Microgrid control systems

Public technical context for microgrid supervisory and communication interfaces. Active and reactive power, generation, load control, operating reserves and system supervision. The application text and educational graphic are independently authored; the publisher does not certify this representation.

SEL · Public reference checked 3 November 2026 · Link only

About this graphic

This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.

SVG and DXF downloads contain this original artwork. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.

Entry JSON · Entry Markdown · Last editorial update: 3 November 2026

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