C5x PTP Link Problems

Can someone please help??

I am installing a C5x PTP and using new equipment straight out of box. I configured and tested this in my office and everything worked fine. Then we took it to the install locations and installed. We have them on about a 75 ft Cat6 Shielded outdoor cable run that has been tested and certified with my test equipment. However, I have tried the 24Volt Mimosa POE which is what I set the units up in my office and the ethernet just keep trying to come up but just blinks and shows cable unplugged. I then got on chat with Mimosa and was told to use the 46V Passive POE like the one that is used with the B5’s so I did but got same results. I am now told to use the 56Volt POE like the ones that are shipped with the A5C AP’s. So does anyone know what is going on? My vendor sold me the 24V POE’s and said they would work which they do using short cables. I haven’t tried the BLACK 56Volt POE yet, but is this the only one that will make them work with longer cable runs? I assume that the voltage is dropping the further the cable run. Other than that, I have no idea. The C5x is an inexpensive radio and I would hate to have almost as much in the cost of a POE as the radio itself.

Anyone else have this problem?
If anyone has deployed the C5x with a cable run of over 75ft, could you please let me know which POE you used.



You are correct that the voltage is dropping over the length of Ethernet cable. So, a higher voltage injector is needed. But the C5x needs a passive injector, which means it does not negotiate the power required, it expects the power is always on. The B5 radios use a different PoE, which negotiates the power requirement before the power is turned on (802.3at), so this will not work with the C5x.
We are running C5x with these 3rd party injectors found on Amazon. They are 48V, and they are passive.
Procet Gigabit Power Over Ethernet PoE Adapter 48V 0.32A,Passive PoE Injector Midspan Plug and Play,EN15G-3: Amazon.ca: Electronics

I need to double check, but I would not recommend using A5c Power supplies, I believe those are 4 pin which I don’t know if C5x’s support…

That said. The C5x should be fine on 75 feet of cable with 24 volts. I power them on that length of cable with 24V Ubiquiti power supplies all the time.

I didn’t know Mimosa even made a 24 V PoE power supply though, I am pretty certain all of their stuff is 48V… I would do a voltage check to make certain that the power supplies are actually working, while you are at it, I would check the amperage that the PoE Injector can supply, could be that over that distance the voltage drop and amperage just isn’t enough.

Mimosa does make and sell a 24v POE. I was told by Streakwave that this was the power supply for the C5x. It is also posted on Streakwave’s site that this is the POE for them.

They work fine on shorter cables but when I use Outdoor Cat6 UTP AWG23 @ 75 Ft, They would not work. Maybe other 24V POE adapters will work fine with the C5x, but the ones purchased from Mimosa do not. I have resolved this by using TP-Link 48V POE’s I purchased from Amazon and they work very well. Another thing I had problems with was the Auto Ethernet Speed setting on the C5x. Had to manually set it to 1000MB instead of using auto. When on auto, the ethernet port on our Mikrotik router would bounce after it started taking on 20 + MB of throughput. Don’t know if this is a Mimosa problem or a Mikrotik problem, just know they won’t work together well using auto ethernet on the C5x.

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The data sheet for the C5x states:
System Power Method: Passive POE (24-56 VDC)
PoE Power Supply: Passive POE compliant, 24-56 V
Power over Ethernet supply (not included)

So as Andy5 has posted and, it appears, you’ve accepted as a solution, you’re 24v supply was being attenuated by the cable length, dropping it below the minimum needed for the C5x.

When I got my lab pair of C5x’s, I ordered the Mimosa official matching power injectors. They’re 56 volt 4 conductor passive. The device will run on 24v but you have much less budget for voltage drop, so I wouldn’t use that at the injector with real runs in the field.

Yea, I’m now using a TP-Link 48V Passive and it works perfect. It’s just when these vendors sell you things that is suppose to work and don’t, it causes problems. Took me a couple days and several test to figure out what was going on. I would not recommend the 24V POE’s for the C5x. The C5x has turned out to be a very good PTP for us at a very affordable price. I love the C5x…