Peripheral unit for a programmable controller

A peripheral unit for monitoring a device of a programmable controller, said peripheral unit comprising:

• a monitor request instruction issuing-side shared memory into which a list of devices to be monitored is written according to a monitor request instruction of a monitoring application executing-section;
• a monitor request instruction issuing unit for issuing the monitor request instruction according to a content of the device list after the device list has been written into said monitor request instruction issuing-side shared memory;
• a communication unit for transmitting a monitor request instruction issued by said monitor request instruction issuing unit to said programmable controller and for receiving the monitor data according to the monitor request instruction from said programmable controller;
• a monitor data obtaining unit for obtaining the monitor data received from said programmable controller;
• and
• a monitor data obtaining-side shared memory into which the monitor data obtained by said monitor data obtaining unit is written, wherein
• said-monitoring application executing-section is given the monitor data from said monitor data obtaining-side shared memory.