| 摘要 |
In a token passing slotted loop network comprising a master station and a plurality of slave stations, a plurality of slots circulating through the loop and each of the slots having a fixed length and comprising a header portion and a data carrier portion, a particular one of the stations having the token transmitting its own data signal by use of one or more of the slots, the particular station transmits an end mark in the header of a particular one of the slots at an end of transmission of the own data signal and strips incoming slots from a start of the transmission of the own data signal until reception of the end mark circulated through the loop. The particular station frees the token by inserting the token in the header of the particular slot. The token can be inserted in the header of one of the slots after completion of the transmission. Each of the slave stations writes into a priority request section in the header of each slot a particular priority request representative of a priority level of the own data signal when the own data signal occurs thereat. The master station writes the highest one of the priority request into a priority section in the header of each-slot. Each slave station detects the priority in the priority section and starts to acquire the token when the detected priority is lower than the particular priority request.
|
