Needs help with POE Device turns on and off over and over.

[Morris computer outlet]

1. I am working on a system that has 8 LCD 8.5 inch screens they're thin clients running with one server I'm trying to use POE to run power and data. So I plug the ethernet into my Cisco 3560 POE switch attached to that is a Cisco RPS 300. Once I plug it into the POE injector on the back of the monitor. it turns up but when it starts to put something on the screen. It shuts right off and turns right back on over and over. What could be the problem?

[WereCatf]

4 minutes ago, Morris computer outlet said:

I am working on a system that has 8 LCD 8.5 inch screens they're thin clients running with one server I'm trying to use POE to run power and data. So I plug the ethernet into my Cisco 3560 POE switch attached to that is a Cisco RPS 300. Once I plug it into the POE injector on the back of the monitor. it turns up but when it starts to put something on the screen. It shuts right off and turns right back on over and over. What could be the problem?

You should've spent a few more seconds on writing your post a bit more coherently, but from what I think you're saying, you're trying to power a thin-client requiring 12V 5A -- 12V * 5A = 60W -- from a Cisco-switch. I looked the Cisco 3560 up and their specsheets says it can only supply 15.4W of power at max on a single port. 15.4W of power is much less than the 60W that your thin-client requires and that's why it shuts down.

[Lurick]

1 hour ago, WereCatf said:

You should've spent a few more seconds on writing your post a bit more coherently, but from what I think you're saying, you're trying to power a thin-client requiring 12V 5A -- 12V * 5A = 60W -- from a Cisco-switch. I looked the Cisco 3560 up and their specsheets says it can only supply 15.4W of power at max on a single port. 15.4W of power is much less than the 60W that your thin-client requires and that's why it shuts down.

Agreed.

OP, what you need is a UPOE capable switch which can supply up to 60W of power.

[WereCatf]

47 minutes ago, Lurick said:

OP, what you need is a UPOE capable switch which can supply up to 60W of power.

Not possible, even the newer PoE-spec only goes up to 30W per port, the older spec only goes up to 15.4W. The tiny wires inside the Ethernet-cables can't handle enormous amounts of current.

[Lurick]

4 minutes ago, WereCatf said:

Not possible, even the newer PoE-spec only goes up to 30W per port, the older spec only goes up to 15.4W. The tiny wires inside the Ethernet-cables can't handle enormous amounts of current.

No, UPOE is rated for 60W of power with another spec in the works for 100W. The UPOE standard does 30w over two pairs and another 30w over the other two pairs. The only thing to note is that UPoE appears to be Cisco proprietary for now. The open alternative, 802.3bt seems to be very new and not widely available yet.

 

http://ciscorouterswitch.over-blog.com/2017/12/cisco-upoe-benefits-and-solutions.html

https://www.belden.com/blog/smart-building/poe-types-what-they-mean-and-how-they-re-used

[WereCatf]

1 hour ago, Lurick said:

The only thing to note is that UPoE appears to be Cisco proprietary for now.

Oh, I see. I've never played around with any Cisco-hardware, so I didn't really have any reason to know of their proprietary stuff, only of the standard stuff. Well, I guess I learned something new again!

 

This said, OP would then need a UPOE-compatible splitter; those TP-Link-splitters claim to support 802.3af, but the specs only speak of up to 12V 1A - output. To be quite frank, I don't think OP's plan of running 8 x 60W thin-clients over PoE is a particularly good one, considering the kinds of investment they'd have to make to make it work.

[Morris computer outlet]

On 2/3/2019 at 10:24 AM, WereCatf said:

Not possible, even the newer PoE-spec only goes up to 30W per port, the older spec only goes up to 15.4W. The tiny wires inside the Ethernet-cables can't handle enormous amounts of current.

Anything is possible watch and learn.. updates coming soon

[Alex Atkin UK]

On 2/16/2019 at 12:46 AM, Morris computer outlet said:

Anything is possible watch and learn.. updates coming soon

Then let us re-phrase, not possible within PoE spec.

[Morris computer outlet]

On 2/17/2019 at 10:42 AM, Alex Atkin UK said:

Then let us re-phrase, not possible within PoE spec.

There is this thing called "PoE+" there is not just one type of "PoE" System. PoE+ has much higher specs then "PoE" Does 

[Alex Atkin UK]

2 hours ago, Morris computer outlet said:

There is this thing called "PoE+" there is not just one type of "PoE" System. PoE+ has much higher specs then "PoE" Does 

I did mean specifically PoE as you never mentioned if changing hardware was an option.

[WereCatf]

3 hours ago, Morris computer outlet said:

There is this thing called "PoE+" there is not just one type of "PoE" System. PoE+ has much higher specs then "PoE" Does 

I already mentioned the newer standard and it's still not enough. Before you go and try to educate others, educate yourself first.

 

There is the IEEE 802.3bt that was defined in 2018, which @Lurick also mentioned, but good luck finding any hardware that supports that, or ethernet-cables that can handle the current!