Monitoring device for programmable controller

A monitoring device for a programmable controller that executes a program written so as to include steps provided for respective operation units of equipment to be controlled and a transition condition between the steps, the monitoring device monitoring the programmable controller, the monitoring device comprising:

• a read device that reads operating state information showing an operating state of the equipment from the programmable controller during individual operation of individually operating the equipment by the operation unit;
• a relationship information storage device that stores relationship information showing relationship between the first step to be executed when the equipment is restarted to resume continuous operation of the steps after the individual operation and the operating state information;
• a selection device that refers to the operating state information and selects from the steps the first step to be executed when the equipment is restarted, based on the relationship information;
• and
• a command transmission device that transmits to the programmable controller a command to change restart position information stored in the programmable controller as information showing the first step to be executed when the equipment is restarted, based on the selection result of the selection device.