Number | Date | Country | Kind |
---|---|---|---|
91 09880 | Aug 1991 | FRX |
Number | Name | Date | Kind |
---|---|---|---|
3555290 | Ellermeyer | Jan 1971 | |
3725818 | Nurmohamed et al. | Apr 1973 | |
4264955 | Goodwin | Apr 1981 | |
4593249 | Aeita et al. | Jun 1986 | |
4617475 | Reinschmidt | Oct 1986 | |
4726026 | Hilford et al. | Feb 1988 | |
4748594 | Iida | May 1988 | |
4862297 | Fukami et al. | Aug 1989 |
Entry |
---|
ISA Transactions, vol. 29, No. 2, 1 Feb. 1990, pp. 13-16, A. A. Frederickson, "Fault tolerant programmable controllers for safety systems". |