EMS contact function

[fly4fn]

This, I hope, should be a simple question. If I am setting up a contact to function through a microswitch that is supplied with 12V system power on the common pin and have the NO output connected to the EMS, what range does the EMS see when the switch is open, 0-2.5 or 2.5-5.0? And will it see the opposite range when the switch is closed? I set one up on EMS pin 11 of the D-37 connector but it seems to see the 2.5-5 volt all the time.

 

[dynonsupport]

That won't work, since the EMS has a 10K pullup to 5V. So basically it's seeing 5V when open, and wants to see ground as its alternate state. So ideally want it hooked to a switch to ground. If you can't do that, if you put a 1K resistor to ground before the switch on the EMS side of things, that will drop the "open" state of the resistor to something like 1V, then you can have open be 0-2.5 and closed be 2.5-5 when it's getting the full 12V.