How the TwinCAT state is controlled

TwinCAT can be set to Config mode using DTE commands; the FreeRun state can be toggled, and the current start state can be queried via the interface.

Requirements

A Visual Studio / TcXaeShell DTE connection is active.

C# sample

// Switch TwinCAT to config mode
dte.ExecuteCommand("TwinCAT.RestartTwinCATConfigMode");

// Switch TwinCAT to run mode
dte.ExecuteCommand("TwinCAT.RestartTwinCATSystem");

// Check if TwinCAT is started (config or run mode)
bool isRunning = sysManager.IsTwinCATStarted();

PowerShell sample

# Config mode
$dte.ExecuteCommand("TwinCAT.RestartTwinCATConfigMode")

# Toggle FreeRun
$dte.ExecuteCommand("TwinCAT.ToogleFreeRunState")

# Check status
$isRunning = $sysManager.IsTwinCATStarted()
Write-Host "TwinCAT läuft: $isRunning"

	The TwinCAT state can be controlled not only using the DTE commands shown here, but also directly via ADS (TwinCAT system service, ADS port 10000).

	`IsTwinCATStarted()` returns `true` when TwinCAT is running, regardless of whether it is in Config or Run Mode. The method thus checks whether a TwinCAT instance is currently running. It serves as a prerequisite for actions that require a running TwinCAT instance, such as an upload. The exact difference compared to a Run Mode test still needs to be verified. Switching to Config mode via `RestartTwinCATConfigMode` is an asynchronous process. For reliable automation, it is recommended to query the TwinCAT state via ADS port 10000 until the Config mode is confirmed.