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urosz
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cAP ac (RBcAPGi-5acD2nD) POE in question

Tue Jul 27, 2021 3:33 pm

Hello,

I have two cap ac access points that I want to power with active POE switch but they don't want to turn on.

The product specification and the user manual states, that cap ac supports PoE in 802.3af/at which is exactly what this little switch does.
https://www.tendacn.com/en/product/spec ... 4-63W.html PoE supply management Port 1 to Port 4 support IEEE802.3at/af PoE standard

If I connect a non mikrotik device to it, different vendor AP or IP phone they both power on immediately, so I guess the switch is not a problem.

If the caps are connected to port 5 of hap ac or included POE injector, both passive POE, they power on without a problem.

Are the cap-ac defective?

Best regards,
Uros
 
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Hominidae
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Wed Jul 28, 2021 12:40 am

cAP-ac definitely works fine with 802.3af/at PoE "supplies"/injectors...I even use them on a small Switch, that is powered via PoE itself, on several occasions.
Anything starting from 12V and a 12W budget should get you going.

...make sure that you use ETH1 on the units when using 802.3at/af PoE and that the tenda is configured with a class-3 device/PSE on that port.
 
urosz
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Thu Jul 29, 2021 9:04 am

Hello,

Thank you for your reply.
The switch doesn't have any special features to setup except one switch on the back to isolate POE ports from talking to each other.

The switch can provide maximum 30W of power per port, that's possible only if you use 1 port, but even if I connect only 1 cap ac to it it doesn't power on.
Snip from the user manual is here https://ibb.co/H7Fxc3q

Cap ac max power consumption is 24 W or max power consumption without attachments 13 W and this 13W setup is what I have. I only use ETH1.

If I connect UniFi UAP-AC-PRO to the switch it powers on without a problem, same with Fanvil X4G IP phone.

Best regards,
Uros
 
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Hominidae
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Thu Jul 29, 2021 10:55 am

I simply doubt that both units are defective (DOA), as both are working on passive PoE injectors.
I just found the cAP-ac to be very tolerant, when it comes to PoE-specs....even with 12V/1A on passive injectors, it will start und run fine.
I never had problems with them in this regard, but I only have about three different brands of 802.3at/af injectors in use and hence experience with.

You could RMA the tenda or exchange it for another Switch or Injector from another brand or try to use this: https://mikrotik.com/product/rbgpoe_con_hp
This will convert a 802.3at/af injector-port into a passive injector. Unifi also has some of these, but with only half the wattage/Amps, I think.

The datasheet for cAP-ac is over exaggerating, when it comes to power draw....according to my Switch, it will go up to something short over 11W, but only on boot.
For example, this is cAP-ac, powered over 802.3at/af (via PoE 802.3at/af powered Switch DLink DGS-1100-05PD) *and* a PoE-Splitter on its ETH2 powering a 12V SIP Phone at the same time...both wireless interfaces on the cAP-ac are currently active with 5 clients and the Phone is connected (on-hook, though):

Image

In short, I'd rather blame the tenda than the cAP-ac...based on my experience.
 
biomesh
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Thu Jul 29, 2021 3:09 pm

My cap ac devices draw under 5W most of the time. I have used different(brands and types of) passive and at/af switches and injectors with no issues.

I suggest trying a different switch(maybe even a different brand).
 
misterbman
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Thu Apr 14, 2022 10:29 am

I have the same combination - a Tenda 4 port PoE switch and MikroTik cAP.
The solution is to use the supplied gray "passive" PoE injector between the switch and cAP - WITHOUT the dc plug connected of course (that would be bad!).
 
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Mon May 30, 2022 5:28 pm

I had the same problem, no way to run directly from PoE ports of a Tenda Switch. But with the solution suggested by misterbman connecting the poe inyectors without energy but as an ethernet bypass between AP and the port at switch side, "magically" all the APs are running taking power from the switch.

Thanks and +10pts to you, Misterbman!
 
gotsprings
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Fri Jun 03, 2022 1:53 pm

Certain switches are just GARBAGE!

The Araknis switches that my boss "can actually get"... Will shut down the port next to a Mikrotik cAP AC. Effectively making the switch 1/2 the size it was sold as. A 24 port switch becomes a 13 port switch is you need to drive 11 cAP ACs. You have to leave 2 ports open so you can have an uplink.

Maybe Tenda OEM'd the same crap.

Ubiquiti EdgeSwitches don't have this problem, and we have used Hundreds.

Mikrotik CRS328-24P-2S+ also does not have this problem. But sometimes chokes on the power needs of my Audience.
 
uCZBpmK6pwoZg7LR
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Mon Jun 27, 2022 5:48 pm

Have same issue with Cisco SG350 and CBS350 poe switches. Everything what i connect to it work except cAP ac.
 
Paulskit
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Re: cAP ac (RBcAPGi-5acD2nD) POE in question

Sat Jan 07, 2023 5:18 pm

Most likely, the reason is Cap not being 802.3 af compliant, supporting only Mode B. This is common for mikrotik devices with stated AF support.
Per standard, both Mode A and Mode B should be supported. POE Switch can implement only one of those.
The reason injector works is they are Mode B by default. Most switches are Mode A. Hence the difference.

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