| 摘要 |
PURPOSE:To make multiplex transmission with a simple circuit by making the primary station connected in loop with plural number of secondary stations send the reset signal, checking and memorizing the connection state of the secondary stations and transmitting/receiving the data by sending poling signal. CONSTITUTION:Plural number of secondary stations 2-6 are connected in loop to a primary station 1 by a two-core transmission cable. The primary station 1 sends a reset signal transmission line 7, and memorizes the number of secondary stations being connected and their types, whether transmission type or reception type. Next, it sends poling signal and trigger signal, and at the same time when it receives data from transmission type secondary stations, it sends data to reception type secondary stations according to the trigger signal. After receiving the poling signal, the transmission type secondary station sends out its own data following the trigger signal, while reception type secondary station receives the poling signal and then sends the trigger signal and then receives the data from the primary station. In this way, multiplex transmission can be done easily even when transmission type and reception type secondary stations are mixed up.
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