| 摘要 |
<p>PURPOSE:To continue communication when a system which operartes a graphic display terminal equipment using an optical cable becomes out of synchronism, without detecting it as an error by placing the system in a non-communication state. CONSTITUTION:In a signal sent from a graphic terminal adapter 3-2 to 3-1, signals F0-F7 for synchronism establishment are tested by an asynchronous detecting circuit 10. When synchronism is normal, an OR circuit 25 is set to a ''1'' and data D0-D2 are fetched in a transmitted data regiter 27 and outputted to a communication processor 2. When an out-of-synchronism state is detected, the OR circuit 25 is set to a ''0'' and in the transmitted data register 27, the last data is held. Consequently, communication control processor 2, is not regarded as an error and is made as if it were in a non-communication state.</p> |
