Programmable controller, programmable controller system, data storage method, and recording medium

A data storage method executed by a programmable controller, the data storage method comprising:

• repetitively collecting, from a memory, a piece of data that is variable;
• when a predetermined first trigger condition is satisfied, recording into a storage a piece of data collected at a timing corresponding to satisfaction of the first trigger condition;
• when a second trigger condition is satisfied, adding additional information to a piece of first data or a piece of second data, each of the piece of first data and the piece of second data being the piece of data recorded into the storage, the piece of second data being collected after collection of the piece of first data, the second trigger condition being different from the first trigger condition;
• and
• after the piece of first data and the piece of second data are recorded into the storage, based on a determination for each of the piece of first data and the piece of second data on whether the piece of data is provided with the additional information, erasing the piece of second data from the storage while retaining the piece of first data in the storage, wherein
• the second trigger condition is a condition requiring for extension of a period of storage of the piece of first data in the storage in comparison to a period in a case of dissatisfaction of the second trigger condition.

A non-transitory recording medium storing a program for causing a programmable controller to:

• repetitively collect, from a memory, a piece of data that is variable;
• when a predetermined first trigger condition is satisfied, record into a storage a piece of data collected at a timing corresponding to satisfaction of the first trigger condition;
• when a second trigger condition is satisfied, add additional information to a piece of first data or a piece of second data, each of the piece of first data and the piece of second data being the piece of data recorded into the storage, the piece of second data being collected after collection of the piece of first data, the second trigger condition being different from the first trigger condition;
• and
• after the piece of first data and the piece of second data are recorded into the storage, based on a determination for each of the piece of first data and the piece of second data on whether the piece of data is provided with the additional information, erase the piece of second data from the storage while retaining the piece of first data in the storage, wherein
• the second trigger condition is a condition requiring for extension of a period of storage of the piece of first data in the storage in comparison to a period in a case of dissatisfaction of the second trigger condition.