Designating a second SSC as an input channel allows designers to implement Boolean logic by combining the sensing output of the Smart Sensor (SSC1) together with that of a second two-state sensor (OSS2) ) operating in SIO mode. In the example shown, the Smart Sensor monitors the presence of an aluminum-foil closure ona bottle, while the secondary photoelectric sensor checks the fill level.
Operating in Boolean ‘AND’ mode, the signal from the secondary sensor is used to enable or disable the Smart Sensor, resulting in the Smart Sensor output (OSS1) being set to ‘high’ only when both sensors are triggered. The output signal on OSS1 is delayed by two milliseconds.
Alternatively, when a Boolean ‘OR’ function is required, a ‘high’ signal from the secondary sensor is set to bypass the Smart Sensor signal, overwriting the SSC1 output. The Smart Sensor otherwise continues to operate normally, and consequently, its output (OSS1) is set to ‘high’ when either sensor is triggered. Again, a two-millisecond delay is introduced.