| 摘要 |
PROBLEM TO BE SOLVED: To speedily and exactly elucidate an abnormal state by providing every terminal equipment with a function for discriminating and displaying normality in the state of communication with the center equipment. SOLUTION: One set of the center equipment 100 and terminal equipment 200 more than one set perform bidirectional communication through a transmission line 300. A communication state diagnostic means 201 diagnoses normality in the state of communication between the present terminal equipment 200 and the center equipment 100. A communication state display means 202 respectively displays the diagnosed result of the communication state diagnostic means 202 in the present terminal equipment 200. Besides, a corrected up signal carrier level is compared with the predetermined allowable range of carrier levels and when the corrected carrier level gets out of the allowable range, it can be displayed on the communication state display means 202 that up communication from the terminal equipment 200 to the center equipment 100 is in the abnormal state. Therefore, the communication state of every terminal equipment 200 for practical use can be diagnosed without using various measuring instruments or the like together and can be displayed at the terminal equipment 200. |
