Title:
【発明の名称】伝送システムのステーションアドレス重複チェック方式
Document Type and Number:
Japanese Patent JP3087391
Kind Code:
B2
Abstract:
PURPOSE:To attain inexpensive and sure processing without need of an exclusive hardware for the detection of duplicate station addresses when a remote I/O is controlled via a programmable controller. CONSTITUTION:A master station implements two kinds of polling to give a token to a slave station. A connection acknowledge polling is sent to a slave station not connected to a transmission line yet till a reply returns and does not send the acknowledge polling to a slave whose reply is returned. An I/O polling is sent to the slave station whose connection is confirmed and a connection acknowledge polling is sent from next when the slave station is not replied. A slave station returns an acknowledge at the leading when the connection acknowledge polling is received from a master station and then an I/O polling is received. When the I/O polling is received before the connection acknowledge polling is received at the rise, since it means that the address is in duplicate with that of other station, the transmission processing is stopped.
Inventors:
Masato Fujii
Application Number:
JP29678691A
Publication Date:
September 11, 2000
Filing Date:
November 13, 1991
Export Citation:
Assignee:
KABUSHIKI KAISHA MEIDENSHA
International Classes:
H04L12/40; (IPC1-7): H04L12/40
Domestic Patent References:
| JP2108341A | ||||
| JP6041835A |
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)