DC523 Input Electrical Connection

Greetings, the DC523 documentation clearly shows that for an input, the "true/false" states are dictated by:

TRUE: Input Connected to UP

FALSE: Input is open circuit

However, our electrical engineer has wired it differently:

TRUE: Open circuit with pullup resistor to UP

FALSE: Input Connected to ZP

Will this new electrical configuration work safely/properly, or do we need to redesign?

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asked 1 year ago




The wiring in the documentation is the norm. Not a absolute.

It all comes down to the amount of voltage present on the Inputs to common.

-3V to +5V is FALSE

15V to 30V is TRUE

Try to keep away from anything 5V to 15V.

Look for the following.

Technical data of the digital inputs/outputs if used as inputs

Hope that helps.


answered 1 year ago


By rdb9879 on 5/1/2017 | Like (0) | Report

That does help, except I am not sure if the voltage requirement will be satisfied because I can't find model of the DC523 input circuit. I would assume that if the input wants 28V/Open, then there is either an internal pulldown resistor, or the input contains an opto-isolator, or maybe even an opto-isolator with an internal current limiting resistor. I would need to know the value of the pulldown or the current requirements of the opto-isolator to determine if our pullup resistor will play nicely. I would normally just hook it up and test it out, but we currently don't have the hardware available.

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