SECU-16 Digital Inputs

[Rick Bonari]

Was wondering if anyone knows if the digital inputs incorporate a pullup resistor?
Thanks Much !!!!!!

[jsteed]

Yes, it does. I believe it's a 1k for supervised, 250 for 4-20mA and none for analog mode.

jim

[kelsky]

According to the instructions:

1) Place a 1Kohm Resistor across the COM and the input that you are connecting the external relay to.

So from this I would say they do not include the resistors.

[jsteed]

The external resistor and the internal one act as a voltage divider which allow the input to be supervised. With the contact open the ocelot sees about 2.5v = OFF. With the wires broken the input will be at 5v=ON and with the contact closed or the wires shorted together the ocelot will see 0v = ON.

This post by glavoie has a little better detail on it: Ocelot Input

jim