When trying to add an APC UPS to either a RB493G or a RB411UAHR via the USB port the drop down box only shows the serial0 port and no USB port option. I’ve tried serveral different OS versions and none of them give me the USB port as an option to connect to the APC UPS. I have tried two different APC UPSs and I am using the factory APC USB to RJ45 data cable that comes with every APC ES550 etc.
What am I missing?
Thanks,
Brad
Just found a RB433UAH laying around and it “sees” serial0, usb1 & usb2 as available options when adding a UPS. It is running v4.10 and is able to connect & monitor the APC UPS statistics without any problem.
I tried downgrading the RB411UAHR to v4.10 and it still does not give me a USB port as an option when trying to add a UPS.
I upgraded the RB433UAH from v4.10 to v5.0 and it still “sees” the serial0 and usb1, but I no longer have usb2 as an option. I am able to choose usb1 when adding a UPS and connect to the APC UPS.
What is different between the RB433UAH and the RB411UAHR & RB493G USB ports and why did upgrading the RB433UAH from v4.10 to v5.0 result in usb2 disappearing?
What do I need to do in order for the RB493G to give me the USB port as an option when adding a UPS?
Thanks,
Brad
i am not 100% sure but ut may be because the USB ports on the RB493G and the RB411UAHR are not powered and you need to use a power injector, maybe. You can just use a powered usb hub.
Possibly, but it think I read in one of the release notes that MikroTik specifically talks about the RB4xx supporting APC UPS monitoring. I don’t think power is needed to communicate with the APC UPS as the UPS is already powered.
Thanks,
Brad
They do support apc ups monitoring AFAIK. Cant hurt trying a powered usb hub.
So, can anyone from MikroTik explain what I may be doing wrong with the RB493G vs. the RB433UAH board? The RB433UAH running v5.0 can see the APC UPS, but the RB493G running v5.0 (or any RouterOS version) cannot.
Is there a specific setting somewhere in the RB493G that enables the USB port to be used?
Thanks,
Brad
Every USB device essentially needs the bus power - to initiate the bus enumeration process correctly. The RB433UAH supplies power to the USB port by default, while RB411UAHR and RB493 doesn’t.
Is this is true and can MikroTik can confirm this? You mention power to the USB port “by default”. Is there a setting to enable power to the RB493G USB port?
If this is correct, than I don’t see the benefit of having a USB port on a RouterBoard that can’t be easily used. Is there some sort of mini USB hub that can be powered by the RB493G, so that the USB port can be used to monitor a APC UPS? Just what we need; more clutter at a site..
Thanks,
Brad
“Default” is incorrect word - the USB power is hard routed at the PCB of the RB433 device, and the power convertor is implied there too and cannot be turned on or off in any way. The first and easiest way for you is to get the USB power injector and external power supply to power up the USB port and make it possible to enumerate USB devices.
The second way is to make some custom power convertor, which could convert the 18 volts of the main power supply downto 5 volts needed by USB port. This convertor has to be soldered to the appropriate pins of USB port. The result is the same, but no external boxes and wires will be used. Such a convertor could be built with LP2950CZ-5.0 linear regulator - but it can provide just 100 mA of current, so this port will be able to communicate self-powered USB devices only.
Same result could be obtained, when DC/DC boost convertor is used - many of them convert from 3.3 volts to 5 volts.
All these voltages (18 and 3.3 volts) are present at RB493’s cooling fan connectors
Ok, using a voltmeter I find the RB433UAH does show 5VDC present on the pins of the USB port, but no voltage present on the RB493G. What a joke…why woud MikroTik do this?
Poking around the RB493G board I find 2.2VDC, 3.3VDC, 7.7VDC, 22.9VDC and 2.2VDC…but no 5VDC. So, where do I go from here? Will tapping into the 7.7VDC be too hot for the APC UPS? Or will tapping into the 3.3VDC be too little voltage? I guess it won’t hurt to try the 3.3VDC…
Thanks,
Brad
Possibly, 3.3 volts will be enough to discover a new connection - there are just some resistors in UPS powered from the USB.
But to make it correct please read my previous message and decide what circuit to build.
I had some time to play with my 3.3VDC idea and it worked! A simple jumper from the 3.3VDC pin to the USB pin was all it took to get the RB493G to recognize the APC UPS. So, it looks like all our RB493G routers will be getting this modification in order for our APC UPS monitoring script to work.
Do we know if MikroTik will make this mistake again on future boards? Will the RB2100 have a USB port with 5VDC or not?
Best,
Brad
RB411U, RB750U and RB433 do supply power to their USB ports
I just checked a RB411UAH here on my desk and there is no power supplied on the USB port. Not sure if you have a newer version than mine or possibly just mistaken.
I am happy to report that the half a dozen or so RB493G’s that I’ve modified are all working well and reporting my APC UPS statistics nicely. I would MUCH rather not have to spend the five minutes modifying each RB493G board to accomplish this and hope MikroTik is listening. Let’s hope MikroTik supplies voltage on the USB port of the up and coming RB2100.
Best,
Brad
Indeed, the RB411UAH and RB411UAHR does not supply power to their USB ports. But RB411U does 
the mentioned boards that don’t supplu USB power need this adapter: http://www.routerboard.com/index.php?showProduct=99
In addition, customer has to purchase an additional 5VDC power supply.
Yuck! What a mess that would make of things hooking all that up. Seems to me the simpler solution is for MikroTik/RouterBoard to make sure all boards have 5VDC present at the USB port! Until then, jumping 3.3VDC across the board is the best solution for us.
We are very interested in the RB2100 due to it’s SFP. Will the RB2100 have 5VDC present at the USB port?
Thanks,
Brad
I got my RB493G board last week and now when I was playing around with it and was going to experiment with a 3G modem connected to the USB, I don’t have a micro-SIM or what form factor this board supports!? Anyway I was playing around with it and noticed that the board didn’t recognize it so I search the forums and found this..
Man was this a disappointment.. And I don’t really understand, why have a USB-port if it doesn’t work without an external powersupply for the USB port?
@BelWave was that all you did? Soldering a cable between those pins? Do you think that can power up a USB 3G dongle or a memory stick?
Thinking about doing this as I don’t want a second powercable and some extra stuff just to get the USB port working..
Thanks,
-Patric
It states, clearly, on the product page that you need power for USB. How can you be surprised/disappointed about something that is mentioned in the product details?