Signal Force Set (Pro)

Force boundary signals to defined values for virtual commissioning and test scenarios

This feature was added in realvirtual 6.3.4 (Professional).

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.

💡 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

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.

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

Add a SignalForceSet component to any GameObject (realvirtual > Professional > Signal Force Set)
Set a descriptive Set Name (e.g., VC_BaseState)
Click the + icon in the Entries list and drag the signal you want to force into the Signal field
Set the desired Value for each entry and add a Comment for clarity
Enable Apply On Start Sim so the base state is always applied at simulation start
Press Apply in the Inspector or start the simulation to activate the forces
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