On 24 August 2013 08:02, aaron moore <aaronmo...@linuxmail.org> wrote:
> Please could someone tell me how to wire 3 wire proximity home switch to my > break out board. That depends on the type of the proximity switch, they come in two types, rather inaccurately called NPN and PNP. http://sensortech.wordpress.com/2011/01/18/industrial-sensing-fundamentals-–-back-to-the-basics-npn-vs-pnp/ When I wired mine it was relatively easy, as I have a 7i64 with isolated inputs, but even then I initially had the sensors on the wrong side of the input. The result of this was the internal LED glowing dimly when "off" and brightly when "on" (though it did actually work). You need to think of them in terms of current flow, not voltage, as they are often used to operate relays rather than logic. The power supply wires are easy enough to figure out, those need a supply of the rated voltage. Then, depending on the type of the sensor, the output wire will either source current (from the positive supply) or sink current (to the 0V wire) when activated. If you have an NPN sensor then it is likely that you can connect the output wire directly to your BoB. The BoB input will (probably) be weakly pulled up to 5V, and when the prox activates then it will be pulled down to 0V. If you have PNP sensors, or if the inputs on the BoB are opto-couplers, then it gets a little more complicated. So, what type of prox sensor do you have, and what is the nature of the BoB inputs (and, also, are the inputs two-terminal floating inputs, or commoned on the +5 or commoned on the 0V side? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Introducing Performance Central, a new site from SourceForge and AppDynamics. Performance Central is your source for news, insights, analysis and resources for efficient Application Performance Management. Visit us today! http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
