Precision DAC and Watchdog Improve Analog Output Safety

Abstract: Using a DAC and a microprocessor supervisor, the system safety can be improved in industrial controllers, programmable-logic controllers (PLC), and data-acquisition systems. The analog output is set to zero-scale (or pin-programmable midscale) when a microprocessor failure, optocoupler failure, or undervoltage condition occurs. A simple application is shown on how to implement this function.
Maxim > Design Support > Technical Documents > Application Notes > A/D and D/A Conversion/Sampling Circuits > APP 474
Keywords: uP supervisor, microprocessor supervisor, analog io, DAC, optocoupler, digital analog converter, programmable logic
controller, PLC, data acquisition
Feb 15, 2012
APPLICATION NOTE 474

Precision DAC and Watchdog Improve Analog Output
Safety
By:Damian Anzaldo, Communication Segment Manager, Maxim Integrated Products
Feb 15, 2012

Abstract:Using a DAC and a microprocessor supervisor, the system safety can be improved in industrial controllers, programmable-
logic controllers (PLC), and data-acquisition systems. The analog output is set to zero-sc