The emergency-stop push button is required on just about every machine, but what other operator interface devices and functions are needed? The human-machine interface (HMI) has many button, indicator, data entry and display capabilities, but it doesn't replace all the functions that can be provided by push buttons, indicator lights, alarm horns and stack lights. When it comes to operator-interface devices, don't be cheap. Include, at a minimum, an emergency-stop push button, a power-off push button, a power-on illuminated push button and a reset push button, each typically mounted in a 22-mm or 30-mm hole. These push buttons and indicators line up well under or beside…Full Story
Development of new connection methods has changed the rules.