An electronic device includes a keypad for data entry, a character recognition system, and a processor. The housing is configured to removably couple about a load line of a lifting device. The two-dimensional and naked eye type stereoscopic switchable display module provides a plurality of stereoscopic image regions in a naked eye type stereoscopic display mode. If the present value deviates from the set value by more than a predetermined amount, the set value of at least one operating parameter can be adjusted. In this arrangement, the sequence processing program can be easily written without considering an internal state transition processing, and the internal state transition processing and the sequence processing program can be freely designed without the need of modifying the sequence processing program due to change of the internal state transition processing.