Cause

No sensor can be generated at the PLC input once the process has been targeted for an sensor. The reason for this can be an incorrect type of signal at the PLC input or there can be a problem with the sensor. The target process can also be missing for a terminal or plug switched to the sensor.

Solution

Double-click the PLC input and then, in the Properties <...> dialog, bring the Symbol / function data tab to the front. Click [Logic]. Check the type of signal for the PLC input in the Connection point logic dialog. This must match the function definition! If, for example, you entered a PLC connection with the function definition "PLC connection point, DI" then the Type of signal must be set as a "digital input"!

Also check whether the type of signal on the sensor is set to "Sensor".

If there is a terminal or a plug between the sensor and the PLC input, check the setting under Target tracking (PLC). A "2" must be entered for the function connection 1 and a "1" for function connection 2.

Refresh the connections and then start a new check run.