Control Wiring - Sinking and Sourcing, NPN-PNP Devices and PLC Inputs
We’re going to talk about sinking, sourcing, PNP, NPN, and how to determine which type of sensor you need depending on your PLC input.
In the video to the right we explain what a Sinking and Sourcing PLC input is, the fact that manufacturers are not consistent with the use of these terms, how they equate to NPN and PNP sensors, and most importantly how to look in the PLC user manual and determine how to wire your control circuit based off of the manufacturer's wiring diagram.
One of the things that people working with plc's get confused on is the use of NPN and PNP devices and connections. Thanks to Terry Woods, a member of the forum at http://www.plctalk.net/qanda/ for providing a very graphical and detailed explanation of NPN/PNP.