The controller involved shall try up to three attempts to operate the turnout back to an original position and vice versa in order to regain a positive detection. If the turnout can be detected, further switching of the turnout should be avoided until the turnout can be examined by the maintenance personnel of the signalling system probably during engineering hours due to the need of track access. If detection cannot be obtained after three attempts, station staff shall be activated at site to inspect the turnout physically under the stipulated rules and procedures for handling a turnout failure as well as safe track access.