Installing the Beckhoff Bridge
Set up the PLC Assist bridge for TwinCAT XAE in under a minute.
The Beckhoff bridge is a small Windows program that attaches to your running TwinCAT XAE. Once started, PLC Assist can read your project, edit Structured Text, build it, and report the errors — all from your browser.
Requirements
| Requirement | Details |
|---|---|
| TwinCAT XAE | 3.1 Build 4024 |
| IDE host | TcXaeShell, the 32-bit XAE shell. 64-bit hosts — TwinCAT 4026's TcXaeShell64 and Visual Studio 2022 — are not supported yet: the bridge attaches but refuses to read the project, and says so |
| Operating System | Windows 10 / 11 (64-bit) |
You also need a PLC Assist account.
Setup
1. Download the bridge
In the chat, the bar at the top says No PLC bridge set up yet. Click Set up a bridge — or go to Settings → Bridges — and under Connect a PLC project click Download for TwinCAT. You get PLCAssistBridge-TwinCAT.zip.
Unzip it somewhere permanent. The download is already tied to your account — there is nothing to copy or paste.
2. Run the bridge
Run bridge\VoltBridgeTwincat.exe. A console window opens and finds your TwinCAT XAE. Either order works: if XAE is not open yet, the bridge waits for it.
That window is the bridge — it stays open for as long as the bridge runs.
Several XAE windows open? Each needs its own bridge: start VoltBridgeTwincat.exe again and it attaches to the next window. Each bridge serves the project its own window has open, and says which one when it starts.
3. Switch back to the browser
The chat connects through the cloud relay on its own — no port, firewall or localhost configuration. When the bridge is attached, the bar shows TwinCAT and the name of your open project.
Stopping the bridge
Close the bridge's console window. That does not touch TwinCAT. The bar then shows PLC bridge not connected.
Updating
Only the latest bridge can reach your project. When a newer one is released, the bar shows PLC bridge needs updating with a Download the new bridge link. Download it, replace the old folder, and run VoltBridgeTwincat.exe again.
Troubleshooting
The bar says "PLC bridge not connected" but the bridge is running
Check that the bridge was downloaded while signed in to the same PLC Assist account as the browser: a bridge belongs to the account that downloaded it. Settings → Bridges lists the bridges of your account.
If the bridge window says it cannot find TwinCAT XAE although the IDE is open, start the bridge as the same Windows user as Visual Studio, with the same elevation (both normal, or both "Run as administrator") — TwinCAT's COM interface does not cross users or elevation levels.
The bar says "Can't reach the connection service"
That is on our side, not yours — your bridge is probably fine. It recovers on its own.
Firewall
The bridge needs outbound WebSocket access to relay.plc-assist.com on port 443. No inbound ports are opened and no port forwarding is needed. If your corporate firewall blocks outbound traffic to that host, allow it.