| 摘要 |
PURPOSE:To simplify the circuit by receiving/transmitting the data between the primary station and plural number of secondary station connected each other in loop by a poling signal and a request signal, and by placing the transmission type and reception type of secondary stations mixedly. CONSTITUTION:Plural number of secondary stations 2-6 are connected in loop to a primary station 1 by a two-core transmission line 7. The primary station 1 sends a poling signal from its output terminal 1-0, and when it receives a request signal from the transmission line 7, it sends out a data signal. Also the primary station 1 sequentially receives the data signal after it sent out the poling signal. Two types of secondary stations are mixed up, the transmission type which transmits the given data signal after it received the poling signal and further sends the poling signal to lower rank stations, and the reception type which sends a request a signal after receiving the poling signal and receives the data and further sends the poling signal to lower stations. Thus, setting of address becomes unnecessary and multiplex transmission can be done by simple circuit.
|
