Select another country or region to see the content that is available for your location
Continue

FAQ

What is the PoE power pins assignment mode A & B?

Answer:

There are two modes of PoE, A and B. Mode A delivers power on the data pairs of 100BASE-TX or 10BASE-T. Mode B delivers power on the spare pairs. PoE can also be used on 1000BASE-T Ethernet, in which case there are no spare pairs and all power is delivered using the phantom technique.

In mode A, pins 1 and 2 form one side of the 48 VDC, and pins 3 and 6 form the other side. These are the same two pairs used for data transmission in 10BASE-T and 100BASE-TX, allowing the provision of both power and data over only two pairs in such networks. The free polarity allows PoE to accommodate for crossover cables, patch cables and auto-MDIX.

In mode B, pins 4–5 form one side of the DC supply and pins 7–8 provide the return; these are the "spare" pairs in 10BASE-T and 100BASE-TX. Mode B, therefore, requires a 4-pair cable.

The PSE (power sourcing equipment), not the PD (powered device), decides whether power mode A or B shall be used. PDs that implement only Mode A or Mode B are disallowed by the standard.

Updated in September 2017

 Mode AMode B
ER52000V 
ER58000V 
ER59000V 
EX74000 V
EX75000 V
EX76000 V
EX78000VV
EX78602V Port 5, 6V Port 1~6
EX78162 V
EX78900VV
EX34000 V
EX45900V 
EX42300V 
EX38000 V
EX45000 V
EX46900AV 
EX46100 V
EX48000 V
EX48000A V
EX49000 V
EX49000A V
EX17008V 
EX17016V 
EX17082V 
X17162  
X17242  
X17908V (Port 2,4,6,8)V (Port 1,3,5,7)
EX17044AV 
EX17008AV 
EX17016AV 
EX17082AV 
EX17162AV 
EX17908AV (Port 2,4,6,8)V (Port 1,3,5,7)
EX24402 V
EX26182V 
EX26262V