June 28, 2024
What is a Passive PoE Switch?
PoE(Power over Ethernet) comes in 2 types, active PoE and passive PoE.
Before we elaborate the differences, lets first look at how a PoE system works.
A PoE system is usually consisted of 3 parts.
PSE=Power supplying equipment
Ethernet Cable=Usually Cat5 or above
PD=Powered device
In this diagram
Industrial PoE Fiber Switch IM-FP244GE and Industrial PoE Fiber Converter IM-PC111GE play the role of “PSE”
IP cameras, wireless AP... act as “PD”
Based on this, when a PSE supplies power to a PD, there is voltage negotiation between in a standard application.
PSE carries Power&Data on the Ethernet cable and will first detect the receiving voltage of PD.
If the supplied and received voltage is roughly the same, then a poe-power connection is built.
Otherwise, PSE will only send networking data to PD.
This is how an active PoE switch works.
For a passive PoE, there is no negotiation. PSE directly supplies Power&Data to PDs.
In this diagram, there is a PoE accessory in the system.
Easy to know that the left Industrial Gigabit Managed PoE Switch IM-FP488GW is an active PoE switch while the IP cameras are not supporting 802.3af or 802.3at standard.
A poe-power connection is not established.
So an extra PoE splitter is added to seperate the power&data and deliver it to the IP cameras via RJ45 and DC connectors.
Now Olycom is presenting a Full Gigabit Passive PoE Industrial switch to solve this.
It eliminates the PoE accessory, simplifies the cabling and saves cost.
Here are some key features about this switch.
This article discussed the features and differences of active and passive PoE. On top of that, it analysed some application diagrams and Olycom new model.
Please let us know if you have any PoE-related projects or queries.
Olycom focuses on indoor and outdoor 802.3bt PoE solutions.
