Posted: 11:27 pm Oct 16 2005
There can be three switched 'states'. A couple of wires may be switched 'on' (connected) or switched 'off' (disconnected). In the instance of logic wiring an input that is not connected to anything 'floats'. Depending on what it's tied to that may be seen as an active input..even though it is tied to nothing.
It's generally considered bad design, but you can 'float' an input to a logic device (tie it to nothing) and have it sensed as active or valid.
Generally you make the input go one way or the other..either tie it to a pullup (to a + voltage) or pulldown (ground for example...maybe a negative voltage).
I included the idea of 'float' just in to cover the possibility.
In this case, it would be VERY unlikely to have anything to do with it.
So...don't get a headache over it!
It's generally considered bad design, but you can 'float' an input to a logic device (tie it to nothing) and have it sensed as active or valid.
Generally you make the input go one way or the other..either tie it to a pullup (to a + voltage) or pulldown (ground for example...maybe a negative voltage).
I included the idea of 'float' just in to cover the possibility.
In this case, it would be VERY unlikely to have anything to do with it.
So...don't get a headache over it!
