Title:
ANALOG INPUT UNIT FOR PROCESSING SIGNAL FOR POWER
Document Type and Number:
Japanese Patent JP3186735
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an analog input unit which can be checked for hardware very accurately with good reliability.
SOLUTION: This unit is provided with a monitoring signal overlaying means 206 for generating a signal for monitoring and overlaying it on an analog signal, an A/D converter 204; a filter operation processing means 200 for executing a first filter operation for extracting the signal for monitoring from a digital signal which has been converted from an analog signal, and a second filter operation for eliminating the signal for monitoring and then taking out signals from the system; a means for judging the normality of the analog input unit from the extracted signal for monitoring; and an output processing means 210 for outputting the digital signal eliminated with the signal for monitoring and the judgement result for the normality of the unit. The signal of monitoring has a frequency higher than the fundamental frequency of the analog signal of the system, and is generated as a signal having such a frequency that the gain of a filter in the second filter operation is smaller than that at the fundamental frequency.
Inventors:
Tomio Chiba
Kido Sanan
Hiroyuki Kudo
Junzo Kawakami
Yoshikazu Yamanaka
Kazuyuki Yokoyama
Takakazu Matsuyama
Tadao Kawai
Shigeru Mori
Kido Sanan
Hiroyuki Kudo
Junzo Kawakami
Yoshikazu Yamanaka
Kazuyuki Yokoyama
Takakazu Matsuyama
Tadao Kawai
Shigeru Mori
Application Number:
JP11102799A
Publication Date:
July 11, 2001
Filing Date:
April 19, 1999
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
H02H3/02; H02H3/00; H02H3/05; H02J3/00; H02J3/18; (IPC1-7): H02H3/05
Domestic Patent References:
| JP61185021A | ||||
| JP61121714A | ||||
| JP63238710A |
Attorney, Agent or Firm:
Kazuko Tomita