> For the complete documentation index, see [llms.txt](https://doc.realvirtual.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.realvirtual.io/components-and-scripts/interfaces/interface-tools/signal-force-set.md).

# Signal Force Set (Pro)

{% hint style="info" %}
This feature was added in realvirtual **6.3.4** (Professional).
{% endhint %}

## Overview

`SignalForceSet` lets you hold one or more PLC signals at fixed values during simulation — independent of what the PLC or simulation logic writes. This is the realvirtual equivalent of the force table in Siemens TIA Portal or Beckhoff TwinCAT: a forced signal always wins against any other writer.

The typical use case is virtual commissioning (VIB), where certain boundary signals have no real source in the simulation but must carry a defined value so the PLC program can run: voltage-present flags, emergency-stop release, system pressure, operating mode — all need to be "forced" to their nominal values before the first cycle can execute.

You can define as many force sets as you need — one per scenario. Multiple sets can be active at the same time.

<figure><img src="/files/qdyqE6TSG5eAMH7qCQrN" alt=""><figcaption><p>The Signal Force Monitor and a force set in the DemoSignalForce sample scene</p></figcaption></figure>

> **💡 Hint**\
> A dedicated **Signal Force Monitor** window shows all active force sets and every currently forced signal in the scene. Open it from **realvirtual DEV > Testing > Signal Force Monitor** or via the **Open Force Monitor** button on any `SignalForceSet`.

## Properties

<figure><img src="/files/MCt3LtEgCeT4B481SsI2" alt=""><figcaption><p>A force set holding the virtual-commissioning base-state boundary signals</p></figcaption></figure>

### General

**Set Name** — Display name for this scenario (e.g., `VC_BaseState`, `TEST_EmergencyStop`). Shown in the Signal Force Monitor for quick identification.

### Entries

**Entries** — List of signals with their forced values. Each entry contains:

| Field                               | Description                                                                                                                     |
| ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| **Signal**                          | Reference to the PLC signal to force (PLCInputBool, PLCOutputBool, PLCInputFloat, etc.)                                         |
| **Enabled**                         | Whether this entry is applied when the set is active. Uncheck to temporarily exclude a signal without removing it from the list |
| **Bool / Float / Int / Text Value** | Target value to force. The visible field matches the signal type                                                                |
| **Comment**                         | Free-text note for documentation (e.g., `"Voltage present"`, `"Automatic mode"`)                                                |

### Behavior

**Apply On Start Sim** — Automatically apply this force set when the simulation starts. Enable this for the VIB base state so the PLC always starts with correct boundary conditions.

**Release On Stop Sim** — Automatically release all forces when the simulation stops. Enabled by default as a safety measure to prevent forces from persisting unnoticed.

### Timed Active

**Timed Active** — Activate the set only within a time window after simulation start, then release automatically. Useful for startup pulses and reset sequences.

**Active From Seconds** — Start time in simulation seconds after which the set becomes active.

**Active To Seconds** — End time in simulation seconds after which the set is automatically released.

### Status

**Is Active** *(read-only)* — Shows whether this force set is currently applied. Visible in the Inspector at runtime for quick status checks.

### Inspector Buttons

| Button                     | Action                                                                                        |
| -------------------------- | --------------------------------------------------------------------------------------------- |
| **Apply**                  | Force all enabled entries immediately                                                         |
| **Release**                | Release all forces from this set immediately                                                  |
| **Capture Current Values** | Read the current live values of all listed signals and store them as the forced target values |
| **Open Force Monitor**     | Open the Signal Force Monitor editor window                                                   |

## Signal Force Monitor

The Signal Force Monitor is a persistent editor window that gives you a scene-wide overview of all active forces.

Open it from **realvirtual DEV > Testing > Signal Force Monitor** or via the **Open Force Monitor** button on any `SignalForceSet`.

<figure><img src="/files/THPuMexakdIEOD8y3p2h" alt=""><figcaption><p>The Signal Force Monitor — force sets on top, all currently forced signals below</p></figcaption></figure>

The window shows:

* **All force sets** in the scene with their current active state and per-set **Apply** / **Release** buttons
* **Watch all forces** — a live list of every currently forced signal, including signal type, current value, forced value, and the source set
* **Release All** button to remove all active forces in one click
* A **persistent warning banner** while any force is active, so no forced signal goes unnoticed

## Quick Start

1. Add a `SignalForceSet` component to any GameObject (`realvirtual > Professional > Signal Force Set`)
2. Set a descriptive **Set Name** (e.g., `VC_BaseState`)
3. Click the **+** icon in the **Entries** list and drag the signal you want to force into the **Signal** field
4. Set the desired **Value** for each entry and add a **Comment** for clarity
5. Enable **Apply On Start Sim** so the base state is always applied at simulation start
6. Press **Apply** in the Inspector or start the simulation to activate the forces
7. Open the **Signal Force Monitor** to confirm which signals are currently forced

## Common Use Cases

* **VIB base state** — Force boundary signals (voltage-present, e-stop released, system pressure, operating mode) so the PLC program can execute its first scan without waiting for missing feedback
* **Test scenario: emergency stop triggered** — Create a dedicated set with the e-stop signal forced to `false` to verify the PLC reacts correctly; switch between sets to compare behavior
* **Test scenario: pressure too low** — Force a pressure signal below its threshold to test protective shutdown logic without modifying physical hardware
* **Startup pulse** — Use **Timed Active** with a 0–2 second window to emit a reset pulse on program start, then release automatically once the PLC has initialized
* **Demo scenes** — Keep a force set with **Apply On Start Sim** enabled so demo environments always start in a defined, runnable state

## MCP Tools

For automation and AI-agent control, realvirtual provides MCP tools to force and release signals programmatically:

* `signal_force_bool`, `signal_force_float`, `signal_force_int` — Force individual signals by name
* `signal_unforce` — Release the force on a single signal
* `signal_force_list` — List all currently forced signals
* `force_set_apply`, `force_set_release` — Apply or release a named force set
* `force_set_list` — List all force sets in the scene with their active state

## See Also

* [Interfaces Overview](/components-and-scripts/interfaces.md) — All available interfaces and signal tools
* [Signal Test Generator](/components-and-scripts/interfaces/interface-tools/signal-test-generator.md) — Generate cyclic test values for interface testing without a PLC
* [Signal Manager](/components-and-scripts/interfaces/interface-tools/signal-manager.md) — Automatically connect and manage large numbers of signals
* [Signal Importer / Exporter](/components-and-scripts/interfaces/signal-importer-exporter.md) — Import and export signal configurations


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