Rockwell CompactLogix Sink and Source input output

Last week I drew a drawing to a client base on an old project in my company using the same compactlogix PLC. I asked buddy here, people said compactlogix sink and source are different than regular people understand. I was too lazy that I did not check back.

I received an email an hour ago. The client said I made mistake on sink and source. It seem like the client goes into "compactlogix sink and source" problem.

Where I can find official information that to show that the funny SINK SOURCE naming problem of compactLogix PLC?

Tofo,

Sink and source are totally different, in fact, their opposite
you can find this information in most any industrial electronics book used in votech schools.

For AB PLC's

a "Sinking Input" card means that +24 volts is applied to the sensor. when the sensor turns on, the input then gets +24 volts to the input and sinks the power to ground. If my memory is correct the sensor is a "PNP" type transistor. it could also be a relay contact or a reed switch.

a "Sourcing Input" card means that +24 volts is applied to the input card common and supplies power to the sensor via the input. when the sensor turns on, the input supplies the +24 volts to the sensor and the sensor sinks the power to ground. If my memory is correct the sensor is a "NPN" type transistor. it could also be a relay contact or a reed switch.

Sourcing input require more power to operate and i have never used one.

you can find the wiring information in the user manuals for the control logix plc.


regards,
james