| 摘要 |
PURPOSE:To make easy to set a suitable level, by transmitting the check data to the reception side prior to the data to be transferred. CONSTITUTION:The check data CD (five types of fixed data a-e and the transmission level is changed to l1-l5 in step) are transmitted from the transmission side in the timing levels t0-t4, and the transmission data TD are transmitted in a given level l3 after the timing t5 (a). Next, only the level in the area DA is detected as the reception data at the reception side, and at the normal reception (b), although all the data a-e in CD are detected, the line loss is greater and when the level of the reception data is as shown in (c), the data a and b are not detected. Accordingly, in this case, it is outputted to the printer that the detection can be made only to the data of the level l2. Thus, when the operator observes this and informs it on telephone set to increase the transmission level only if the data having the digit in which no TD is detected is present, it allows normal reception. |
