Bosch Rexroth ctrlX (Pro)
Bosch Rexroth ctrlX OS interface with Data Layer bridge integration (Pro)
The ctrlX Interface is currently in Beta and will be officially released with realvirtual Professional 6.3.
Overview
The ctrlX Interface connects realvirtual directly to any ctrlX OS device like the Bosch Rexroth ctrlX CORE controller. It uses the realvirtual WebSocket Bridge — a .NET 8 snap application running on ctrlX OS — to exchange PLC signals in real time via the ctrlX Data Layer.
Communication uses the high-performance WebSocket Realtime Interface v2 protocol, enabling cyclic signal exchange at millisecond intervals. The ctrlX Interface extends the WebSocket Realtime Interface with ctrlX OS-specific features: REST API authentication, device status monitoring, remote bridge configuration, ctrlX Data Layer settings, and diagnostics — all from the Unity Inspector.
Key capabilities:
High-speed signal exchange via WebSocket with configurable publish intervals down to 5 ms
One-click signal import from ctrlX Data Layer with automatic signal discovery
REST API integration for device info, bridge status, and diagnostics
Remote bridge configuration (publish interval, browse paths, logging level)
Data Layer settings (min publish/sample intervals)
SSL/TLS support for secure connections through the ctrlX reverse proxy
Architecture
Unity (realvirtual) ctrlX OS device
┌─────────────────────┐ ┌──────────────────────────────┐
│ │ │ │
│ ctrlX Interface ──┼── WebSocket v2 ──▶ WebSocket Bridge │
│ │ │ │ │
│ ───┼── REST API ─────▶ ctrlX Data Layer │
│ │ │ │ │
│ │ │ PLC Runtime │
│ │ │ │
└─────────────────────┘ └──────────────────────────────┘The ctrlX Interface communicates with ctrlX OS devices through two channels:
WebSocket v2 — High-speed cyclic signal exchange using the WebSocket Realtime Interface v2 protocol. See that page for the full wire format specification.
REST API — Authentication, device info, bridge configuration, Data Layer settings, and diagnostics.
realvirtual WebSocket Bridge
The realvirtual WebSocket Bridge is a .NET 8 snap application that runs on ctrlX OS. It bridges the ctrlX Data Layer to realvirtual Unity Digital Twins via the WebSocket Realtime Interface v2 protocol.

The bridge includes a built-in status page accessible via the ctrlX OS web interface, showing connection status, signal counts, write activity monitoring, and browse path configuration at a glance.

The bridge:
Subscribes to ctrlX Data Layer nodes and publishes their values over WebSocket
Receives signal updates from Unity and writes them back to the Data Layer
Supports configurable browse paths, publish intervals, and logging levels
Can be configured remotely from the Unity Inspector
Setup
Prerequisites
A ctrlX OS device like ctrlX CORE (physical or virtual)
The realvirtual WebSocket Bridge snap installed on the ctrlX OS device (available from realvirtual on demand)
Network connectivity between your PC and the ctrlX OS device
Adding the Interface
In Unity, go to the menu Tools > realvirtual > Interfaces > ctrlX Interface to add the component
Enter the ctrlX Address (IP address of your ctrlX OS device)
Set Username and Password (default:
boschrexroth/boschrexroth)Click Refresh to verify the connection and see device info

Importing Signals
Make sure the ctrlX OS device is reachable and the bridge snap is running
Configure Browse Paths to point to your PLC symbols (e.g.
plc/app/Application/sym)Click Import Signals in the Connection section
The interface connects to the bridge, discovers all signals, and creates local PLC signal objects as children
Quick Start
Add the ctrlX Interface to your scene
Enter ctrlX address and credentials
Click Refresh to verify connectivity
Configure browse paths for your PLC program
Click Import Signals to create signal objects
Press Play — signals exchange automatically
Properties
Connection
ctrlX Address
IP address of the ctrlX OS device (e.g. 192.168.1.1)
Username
Login username for ctrlX REST API (default: boschrexroth)
Password
Login password for ctrlX REST API (default: boschrexroth)
Use SSL
Enable for wss:// connections through the ctrlX reverse proxy. When enabled, port switches to 443 and path is set automatically
Status
ctrlX
Device info: operating mode, hostname, OS version, architecture
Bridge
Installed bridge snap version and status
WebSocket
Current WebSocket connection state (Connected / Disconnected)
Signals
Number of input and output signals
Comm Cycle
Actual communication cycle time in milliseconds
Config
Last configuration operation result
Buttons:
Refresh — Fetches device info and bridge status from ctrlX via REST API
Test ctrlX — Tests REST connectivity by authenticating and reporting the result
Test Bridge — Tests WebSocket connectivity to the bridge application
Signal Import Configuration
Default Direction
Direction for imported signals when no pattern matches (Input or Output)
Use Pattern Matching
Enable name-based direction detection using the patterns below
Input Patterns
Name substrings that identify signals Unity writes to the PLC (e.g. "Unity")
Output Patterns
Name substrings that identify signals the PLC writes to Unity
Bridge Configuration
Publish Interval (ms)
How often the bridge publishes signal updates over WebSocket (default: 5 ms)
Logging Level
Bridge log verbosity: Debug, Information, Warning, or Error
Browse Paths
Data Layer path prefixes for signal auto-discovery (e.g. plc/app/Application/sym)
Recursive
Browse sub-folders recursively when discovering signals
Changes to bridge configuration are tracked and auto-applied after a short delay.
Data Layer Settings
Min Publish Interval (ms)
ctrlX Data Layer global minimum publish interval in milliseconds (default: 10)
Min Sample Interval (µs)
ctrlX Data Layer global minimum sample interval in microseconds (default: 10000)
Buttons:
Get DL — Reads current Data Layer subscription settings from ctrlX
Apply DL — Writes the configured values to ctrlX Data Layer settings
Bridge Logs
Log Count
Number of log entries to fetch from ctrlX diagnostics
Bridge Logs Only
Filter to show only bridge snap log entries
Forward to Console
Write each fetched log entry to the Unity console
Buttons:
Fetch Logs — Retrieves recent log entries from ctrlX OS diagnostics
List Packages — Lists all installed snaps on the ctrlX OS device
Advanced
WebSocket Port
TCP port for WebSocket communication (default: 8080, auto-set to 443 when SSL is enabled)
Update Cycle (ms)
Communication thread update interval in milliseconds
Client Name
Identification name sent during WebSocket handshake
Connect On Play
Automatically connect when entering play mode
Only Transmit Changed
Only send signals whose values changed since the last cycle
Auto Reconnect
Automatically reconnect on connection loss
Debug Mode
Enable detailed logging for troubleshooting
SSL / Reverse Proxy
When Use SSL is enabled:
The port is automatically set to 443
The WebSocket path is set to
/ctrlx-rv-bridge/wsfor routing through the ctrlX reverse proxyAll REST API calls use HTTPS
Self-signed certificates are accepted (common for ctrlX devices on local networks)
When SSL is disabled, the interface connects directly to the bridge on port 8080 without encryption.
Troubleshooting
"Refresh" shows no device info:
Verify the ctrlX address is correct and the device is reachable (
ping)Check username and password — default is
boschrexroth/boschrexrothUse Test ctrlX to verify REST API connectivity
Bridge shows "not found":
Install the realvirtual WebSocket Bridge snap on the ctrlX device
Check that the snap is in
activestate
WebSocket stays "Disconnected" during play:
Verify the bridge snap is running on the ctrlX OS device
Check WebSocket Port matches the bridge configuration (default: 8080)
If using SSL, ensure port 443 is accessible and the bridge is behind the ctrlX reverse proxy
Enable Debug Mode for detailed connection logging
Signals not importing:
Check that Browse Paths point to valid Data Layer nodes (e.g.
plc/app/Application/sym)Enable Recursive to discover signals in sub-folders
Verify the PLC application is loaded and running on the ctrlX OS device
Wrong signal directions after import:
Configure Input Patterns and Output Patterns to match your naming convention
Or set the Default Direction to match the majority of your signals
See Also
WebSocket Realtime Interface (Pro) — Base protocol, wire format specification, and code examples
Custom Interfaces (FastInterface) — How to build your own interfaces
Signal Manager — Managing PLC signals
Interfaces Overview — All available interfaces
ctrlX OS Overview — Information about ctrlX OS
Bosch Rexroth ctrlX AUTOMATION platform — Information about the automation toolbox
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