# Digital Signal Diagnostics

During deployment and during troubleshooting of a controller, a diagnostic tool is very helpful. It is available for the analysis under the Info tag for a device configuration or a fieldbus mapping in the Virtual station menu.

The controller can operate in normal mode or in diagnostics mode. In normal mode the digital input and output signals operate normally and are routed between the internal controller logic and to an external accessory or a connector.

The diagnostics mode is divided into monitor mode and forced mode. In the monitor mode signals operate normally, but provide live monitoring of the signal behavior. In forced mode the connection between the controller internal logic and the external accessory is opened and the input and output signals can be forced to a desired state.

It is possible to diagnose digital signals for one device or one fieldbus at a time.