| 摘要 |
PURPOSE:To attain communication between slave stations by circulating twice the communication to one polling in a loop line to expand the 1:N communication system to the N:N communication system. CONSTITUTION:In case of transmission from a slave station to another slave station, a text including a destination address is transmitted to a loop master station at the 1st circulation at first. The master station receives the text, rearranges fields of the address and changes it into a frame format reaching the substantial destination slave station. The master station transmits the modified test at the 2nd circulation. That is, a polling (a) is transmitted from the loop master station to the slave station B. Then the slave station B transmits a text (b) for a slave station D including the address of the slave station D to the loop master station. The loop master station rearranges the address field of the text (b), converts it into a text (c) for the slave station D and transmits it to the slave station D at the 2nd circulation of the loop. |
