| 摘要 |
PROBLEM TO BE SOLVED: To provide a field bus system working in a multi-drop wiring configuration where slaves with the different number of inputs/outputs are allowed to coexist. SOLUTION: In this field bus system, the frame length of an IN frame decided based on status information including the number of inputs/outputs stored in a slave 20 and the transmission timing of each IN frame calculated based on the order of slaves which transmit the IN frames are stored in the register of each slave. When each slave has received OUT frame from a master, a timer is started, and when the timer value reaches the transmission timing stored in the register, each IN slaves transmits its own IN frame. The intervals of the transmission timings are not made equal, but decided according to the frame length so that each IN frame can be transmitted without bumping each other. COPYRIGHT: (C)2005,JPO&NCIPI
|
