HOME › Forums › Input/Output › EZIOxx › EZIO2X4 – How to use I3/I4 as simple "dry contacts" › Reply To: EZIO2X4 – How to use I3/I4 as simple "dry contacts"
Yes a pull up would be needed.
Connect a 10,000 Ohm 1/4 Watt resistor from I3 to +5 volts and a 10,000 Ohm 1/4 watt resistor from I4 to +5.
Then connect the dry contact switch from I3 and Ground and the other dry contact switch from I4 and Ground.
A 4,700 Ohm resistor would also be fine for the pull up resistors.