Sensors Frequently Asked Questions
Sensors Frequently Asked Questions
| Question | How do I determine which type of proximity sensor output I need, NPN or PNP? |
| Answer | PNP sensors are current sourcing devices and NPN sensors are current sinking devices. A current sourcing sensor must be connected to a current sinking input. Likewise, a current sinking sensor must be connected to a current sourcing input, so you must know the input circuitry of the device you are connecting with the sensor. Most AutomationDirect PLC input modules (except 305 series) allow NPN or PNP sensors to be connected. This is sometimes determined by what other type of devices are being connected to the PLC module. |
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This item was last updated on 11-30-2007
Document ID: 459
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