It is over for the time,'' answered Rebecca; ``our friends strengthen themselves within the outwork which they have mastered, and it affords them so good a shelter from the foemen's shot, that the garrison only bestow a few bolts on it from interval to interval, as if rather to disquiet than effectually to injure them.
PnP. 1. Short for Plug-and-Play. PnP is an ability of a computer to detect and configure hardware automatically, without requiring the user to physically configure the hardware with jumpers or dip switches. Plug-and-Play was introduced on IBM compatible computers with the release of Microsoft Windows 95.
Now, one of the old guys! In PLC work NPN means the sensor or switch connects to the negative of the power supply. When the sensor is made up it connects the plc input to the negative and makes up the PLC input point. The PNP is the same except it connects the PLC input to the positive side of the supply. In most of my plc work we use NPN type sensors.