Dell 3524P PoE switch

[dave_siew]

I have a Dell 3524P PoE switch that supports IEEE 802.3af.

It uses Type B power output, says Dell.

The IEEE standard indicates, I am told, that devices should expect power Type A or Type B (different pair pos/neg)

I see on some Internet references that the 7940G does not conform to the IEEE 802.3af standard by not accepting Type B power supplies. I am told that I can make or Cisco can supply a dongle to swap wire 1 and 4 to convert Type A to Type B and allow the 7940G to work.

Have you all heard of this?

Thank you

[Rob Huffman]

Hi Dave,

You are most correct in that the 7940 and 7960 models are supported by Cisco pre-standard power and not IEEE 802.3af as shown below;

Q. What IP phone models support the Cisco pre-standard method of powered device detection?

A. These Cisco IP phones can accept Cisco pre-standard PoE from a card integrated with a Cisco Catalyst switch or a Catalyst in-line power patch panel:

7985G

7960G

7940G

7910G

7910G + SW

7912G

7905G

7902G

These phones can draw local power from a power cube (CP-PWR-CUBE-2=) in addition to a country or regionally specific power cord (CP-PWR-CORD-xx=).

Q. What IP phone models support the IEEE standard method of powered device detection?

A. These Cisco IP phones support IEEE 802.3af PoE:

7961G-GE

7971G-GE

7931G

7911G

7941G-GE

Note: These Cisco IP phones support both the Cisco pre-standard PoE and IEEE 802.3af PoE:

7970G

7961G

7906G

From this doc;

Power over Ethernet (PoE) Power Requirements FAQ

http://www.cisco.com/en/US/products/hw/phones/ps379/products_qanda_item09186a00808996f3.shtml

I have not tried these products, (Cisco PoE switches are all backwards compatible) but this is what you are referring to;

PD-PS-401-Cisco Passive splitter for Cisco

http://www.simnetsa.ch/upload/File/Microsemi/PowerDsine_Product_Selection_Guide.pdf

http://microsemi.com/PowerDsine/Documentation/SelectionGuide/SelectionGuide.pdf

Hope this helps!

Rob