Communications system for position detector

A communications system for a position detector, comprising:

• a position detector for detecting an amount of movement of a machine;
• an A/D converter connected to the position detector;
• a numerical control device connected to the A/D converter and receiving a position signal converted by the A/D converter;
• and
• an information processor connected to the A/D converter via bidirectional communication means capable of bidirectional communication,
• wherein the information processor is a device including a storage section for preserving data and a program, a computing section for computationally operating the program, and a display section for indicating results of computational operation by the computing section, and the data, and
• wherein the program has a function of indicating an abnormality on the display section, if none of position data on the position detector, internal state data on the position detector, manufacturer's serial number data on the position detector, model data on the position detector, version data on the position detector, internal signal data on the position detector, and abnormality data on the position detector can be obtained, or if the abnormality data on the position detector has been received, or if the internal signal data on the position detector deviates from an allowable value.