Sequence-program design support device

A sequence-program design support device comprising:

• a screen display unit that displays a work screen corresponding to a work in designing a sequence program of a programmable logic controller;
• an input unit that receives a setting operation to set work phases in designing the sequence program, a zoom-in operation accompanied by a first operation amount, and a zoom-out operation accompanied by a second operation amount;
• a work-state storage unit that stores therein the work phases received by the input unit and a current work;
• a work-model storage unit that stores therein an order of works for performing the work phases together with a work screen corresponding to the work;
• and
• a display control unit that displays a work screen corresponding to a next work following the current work in the order on the screen display unit and stores the next work in the work-state storage unit when the input unit receives the zoom-in operation with the first operation amount being equal to or larger than a first threshold, and displays a work screen corresponding to a previous work preceding the current work in the order on the screen display unit and stores the previous work in the work-state storage unit when the input unit receives the zoom-out operation with the second operation amount being equal to or larger than a second threshold.