Click on “Download PDF” for the PDF version or on the title for the HTML version. If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options. An External Watchdog Circuit for Microcomputer-Based ControllersPublished by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org Citation: Applied Engineering in Agriculture. 2(1): 33-35. (doi: 10.13031/2013.26704) @1986Authors: J. D. C. Baldwin Keywords: Agricultural safety, Automation, Controller, Timer AN external watchdog timer circuit for microcomputer-based controllers is presented. The controller must continually retrigger the timer to keep the control system active. A relay that remains energized while the system is operating properly actuates an alarm circuit and disconnects a power source if the timer is allowed to complete its cycle. A software technique to help detect incorrect program flow is also presented. (Download PDF) (Export to EndNotes)
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