# Microgrid site-controller watchdog interface

Canonical URL: https://eloragrid.ai/symbols/microgrid-site-controller-watchdog-interface
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: MSWI
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: microgrids
Input: Controller watchdog output
Output: Site-controller fault indication

Transfers the controller's declared self-health output to independent supervision.

## In plain English

### What this block does

Transfers the controller's declared self-health output to independent supervision.

### 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 “Controller watchdog output” at the input and “Site-controller fault indication” at the output. Watchdog coverage has defined limits.

### What the drawings help you do

Start at the named input: Controller watchdog output. Identify its source device or document and the state represented on the drawing. Follow the named output: Site-controller fault indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Controller watchdog output
- Output: Site-controller fault indication
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Controller watchdog output → MSWI → Site-controller fault indication
A reading guide. The entry's original illustration and input/output facts describe this application.

- [Microgrid control systems](https://selinc.com/services/microgrids-power-management/microgrid-control-systems/)


## What it represents

Transfers the controller's declared self-health output to independent supervision. 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 “Controller watchdog output” at the input and “Site-controller fault indication” at the output. Watchdog coverage has defined limits.
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: Controller watchdog output. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Site-controller fault indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Watchdog coverage has defined limits.
- 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 controller watchdog output.
- Identify the destination and defined state of site-controller fault indication.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Watchdog coverage has defined limits.

## Important distinction

Watchdog coverage has defined limits. 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.

## Facts

- Representation: Functional block
- Installation focus: Microgrids
- Input / boundary: Controller watchdog output
- Output / connection: Site-controller fault indication
- Lookup label: MSWI is a library lookup label, not a standard device designation.

## Public references

- [Microgrid control systems](https://selinc.com/services/microgrids-power-management/microgrid-control-systems/) — SEL. 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.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.