Programmable controller monitor device

Abstract

Abstract PURPOSE:To obtain a high-speed, flexible communicating function while minimizing the load on a main CPU by connecting a subordinate CPU exclusive for communication control to the main CPU through a dual port RAM and gathering information from plural PCs through this subordinate CPU. CONSTITUTION:When the numbers of programmable controllers (PC) and reference numbers in respective PC are specified, the setting procedure generation part 11 of the main CPU generates a table 12 for the reference numbers based on the information. Then, an optimum procedure generation part 13 generates subordinate CPU control information 14 based on the reference number table. The algorithm of the optimum procedure generation part 13 performs sorting according to the PC numbers and reference numbers and then groups information within a range wherein the information is obtained through a bus 7 by making a communication once. Then, control information 14 is placed on the dual port RAM 5 in line mode, the subordinate CPU 6 begins to scan the PCs individually on the basis of the control information, and the main CPU 3 obtains usually up-to-date information thereafter only by checking the dual port RAM 5.

Inventors

• 👤 Shigeru Yamamoto
• 👤 山元　茂

Bibliographic Details