| 摘要 |
PROBLEM TO BE SOLVED: To provide a data processor which can secure normal communication even if abnormality occurs in a line. SOLUTION: A data processor 10 and an external input/output unit 20 are connected by a plurality of lines 30. A line abnormality detection means 11 transmits a request signal on the line to be used and a response signal is generated from a response means 21. The line abnormality detection means detects an abnormality of the line according to whether the response signal is received or not, and a line switching means 16 switches the line to be used when an abnormality occurs in the line to be used. |
