| 摘要 |
<p>PROBLEM TO BE SOLVED: To self-diagnose the function of a test function by connecting a test cell generation part and a test cell inspection part with a return means and giving a test cell generated in the test cell generation part to the test cell inspection part. SOLUTION: At the time of self-diagnose, selectors SEL1-4 are switched so that a route B is selected with the control signal of MPU. In a transmission part 4, the test cell generated in the test cell generation part GEN is transmitted not to a test cell insertion part INS but to a return buffer 6. The test cell is given to the test cell inspection part CHK via the return buffer 6 and the selector SEL1 of a reception part 1, and the test cell is inspected. The relation of a transmission part 2 and a reception part 3 is the same. The test cell generated in the test cell generation part GEN is transmission from the selector SEL2 to a return buffer 7. The test cell is given from the return buffer 7 to the test cell inspection part CHK via the selector SEL3 of the reception part 3.</p> |
