Programmable display device

A programmable display device, comprising:

• a programmable display device main body having a self-identifier as an identifier unique to the programmable display device main body;
• and
• an external storage medium attachable to and detachable from the programmable display device main body,
• the external storage medium storing data to be read by the programmable display device main body and further storing at least one of (i) an identifier-storing file containing a record identifier that is associated with the data and that is indicative of the self-identifier and (ii) a setting-information-storing file capable of containing setting information that is associated with the data and that is for use in authentication of the data,
• the programmable display device main body including:
• an identifier-storing-file detecting section for detecting whether an external storage medium storing the data and connected to the programmable display device main body stores the identifier-storing file;
• a setting-information-storing-file detecting section for detecting whether the external storage medium connected to the programmable display device main body stores the setting-information-storing file;
• and
• a data reading section for reading the data,
• the data reading section not reading the data in a case where the external storage medium connected to the programmable display device main body stores neither the identifier-storing file nor the setting-information-storing file, and
• a setting information detecting section for, in a case where the external storage medium connected to the programmable display device main body stores the setting-information-storing file, detecting whether the setting-information-storing file contains the setting information;
• and
• an identifier-storing-file creating section for, in a case where the external storage medium connected to the programmable display device main body stores the setting-information-storing file and the setting-information-storing file does not contain the setting information, (i) creating an identifier-storing file containing the self-identifier of the programmable display device main body as the record identifier and (ii) writing the created identifier-storing file to the external storage medium connected to the programmable display device main body.