Hello, is the pwr-line feature of the hAP lite stable? I’m wondering because I could not find this feature on the product page https://mikrotik.com/product/RB941-2nD-TC. The documentation was not enlightening either https://help.mikrotik.com/docs/display/ROS/PWR+Line.
Thanks & best
Quote from the link you posted that answered your question. 
Supported Hardware
The device is fully compatible with our PWR-LINE AP and the newest revisions of products that have a microUSB port,
such as- > hAP lite> , hAP lite tower, hAP mini, mAP and mAP lite have pwr-line interface. A simple software upgrade to v6.44+
enables this feature (supported by the mentioned devices with serial numbers that ends with /9xx). PWR-LINE functionality
is also supported by some of previously manufactured units - if you have unit with serial number that ends with /8xx,
upgrade to 6.44+ and see if pwr-line interface shows up).
Hi,
I have used a bunch of MT PL7400 (PWR-LINE EU) plugs with HAP mini and MAP lite. I guess HAP lite will work the same.
I have use 6.48.x and 6.49.x ROS, they all worked stable on the software side.
Beware however out of the 6 PWR-LINE EU plugs I have used, 3 are constantly going down and up. That happens since their first days. They are totally uselessly flapping.
So there seems to be some kind of HW issue with some of those. I guess it did not affect every production run.
I never opened a ticket or troublshooted them myself…
Regards
@smyers119
Thanks for your reply. How does this quote answer my questions? Or do you think fully compatible equals runs stable? If so, ok. I thought this would be a bold assumption.
AFAIK this feature was introduces 2018. Hence, I’m wondering what could be the reason that this features is not listed on the product page. My best guess was “it should work on those devices but do not rely on it because it lacks stability/performance whatever”. To get clarity, I asked.
@woland
Thanks for sharing. Interesting that your hAP mini run stable but the dedicated power line devices do not.
AFAIK hAP lite and hAP mini are nearly identical despite the number of ports. And I looked up the product page of the hAP mini. I could not find any hint about power line support either.
Actually, I did not plan to use power line for LAN at all due to bad experience some 20 years ago. But since its a free feature of the current hAP lites, I’ll give it a try and see if it runs stable enough to expand my IoT network.
Thanks & best
The plugs do work well enough and stable (no problems for years, except with the ones with the manufacturing defects) for some situations, just don´t expect huge throughput. I have been using them since maybe 2 years for temporary or low traffic connections if no cabling present and it is not worth it to install more cables.
The HAP and MAP devices themselves are rock solid, none of them have failed (I have used something like 15 pieces). Just don´t try to upgrade them with ROS 7.x and do not expect high bandwidth and coverage.
Thanks for the feedback. I’m optimistic that this could actually fit my needs. New cables are not possible ATM, so I aimed for WiFi bridge. But if pwr-line is stable I’ll give it a try since my IoT network does not need bandwidth.
Am I misreading you? I should not upgrade to ROS v7.x? Actually, i did upgrade the new device today (to version 7.6). And I planned to upgrade the second device, which comes this week I hope, as well.
Are there known problems with pwr-line? I read the change log but nothing jumped out at me. Despite what I read in another thread that hAP lite’s performance is a bit worse with 7.x. I thought that this would not be an issue due to the low traffic and few devices (10-14 IoT devices) connected.
Best
I am still using 6.49.x in most of my MT devices except on devices, which don´t support 6.x. It´s more stable and it gives you more performance. I also don´t need anything from the newer 7.x features.
I have tried 7.x (maybe 7.3) once wth one of my HAP minis and it got very unstable, and also less responsive. It took ages to generate a config export and the CPU was over 10% , while it was just idling.
I did not test Powerline with ROS7 and I did not compare performance.
Also if you read this board: I think the general consensus still is, to stay on ROS 6 as long as you don´t need to go to 7, because of the stability and performance issues.
You can´t easily downgrade to 6.x if you have upgraded to 7.x, but you can always do a netinstall to 6.x… Search the forums and help.mikrotik.com , there is lot´s of useful info on this topic.
You should consider the hAP lite and hAP mini basically as toys. They have so little storage that they cannot be upgraded to RouterOS v7 and when running v6 you will find that they often fail to upgrade to a new version and have to be netinstalled.
Also the WiFi driver in the most recent stable version is performing really terrible due to the fix of some “university research security hole”.
You can run an older long-term version instead. But it basically is a dead-end. I would not invest in it when you are now considering buying it new, especially when it is more than 2 devices for some special temporary connection.
correction:
all SMIPS models
(if there are other models)
Well I am not using them as toys, but as low speed and very low power devices, with powerline support. The physical size is unbeatable. Should they get stolen, well I wouldn´t be happy, but I definitely wouldn´t loose any tears.
If you netinstall them with the packetized ROS6 and remove unneeded packages, you can always upgrade them afterwards.
Also I have successfully installed ROS7, but I dont recommend using it,see my previos post!.
They have the same amount of flash like most other APs from MT have: 16Mb. They just have slower CPUs.
No I would not use them if I´d build something serious, no, not even my uplink routers at my home are hap minis.
This leads me to a very obvious next idea: would I use MT at all in some big network, where money is less of a problem? Probably no…
Different use cases need different devices. High performance is not the benefit of using these, but stable low powered operation definitely is!
Thanks all for the replies.
If the WiFi is weaker/unstable with v7.x, I’ll do a netinstall on my new device and I’ll stay with 6.x LTS. None of my hAP lite can be accessed from outside and there is no other relevant security threat.
My main reason for liking the hAP lite is the low power consumption - and also its price-performance ratio is IMHO excellent.
Best
The big difference is that they have only 32MB of RAM, and hence no space for a RAMdisk.
In the other models with 16MB flash (which usually have 128MB or more RAM) the upgrade packages are downloaded into RAMdisk and the installation can take place in the 16MB flash without disturbance.
In the hAP lite and hAP mini, the packages are downloaded into flash (just like in the models with >16MB flash) and so there has to be space in the flash for:
- the existing installed RouterOS
- the newly downloaded upgrade packages
- the working space during installation
In practice that means that even an existing combined-package v6.xx install as it comes from the factory can only be upgraded for a limited number of times, until due to the always occurring space leakage there is no more room on the flash.
Indeed as mentioned you can escape the certain death by using a separate-package install and have only the packages required for your usage on the device, especially when that usage is only a simple access point and no advanced features.
But in v7 that is no longer possible, and v7 will be guaranteed problems.
The last version that works correctly is 6.47.9
The big difference is that they have only 32MB of RAM, and hence no space for a RAMdisk.
Thanks, this explains the issues with the upgrades I had.
So that´s one more reason not to go with v7.
I was using the latest 6.48.x-6.49.x without any issues, but only for short range, low speed. I have read this advice about 6.47.9 already, but I don´t know the reason for this.
Is it related to the TX power setting, which is not available in newer versions?
Is it related to the TX power setting, which is not available in newer versions?
No, it is related to issues with the ROS 7.x WiFi driver for hAP lite and hAP mini.
TX power was removed to comply with regulation.
But contrary to popular belief, increasing TX power does not help much anyway. WiFi is bidirectional, and if the STA can’t get its signal back to the WAP, there is no connection.
The range of a WAP is mostly determined by the radio RX performance (SNR, noise immunity and effective selectivity of radio RX circuits).
Thanks jbl42!
ROS 7 is out of question. If it´s not the tx power limit (which afaik can be overridden by the cli anyhow), then what could it be?
I think I have to rephrase my question: what´s better in 6.47.9 wifiwise than with 6.49.7 ?
pe1chl wrote it, that there was some bug or weakness introduced, but I could not find out, what that exactly that was?
I have seen this suggestion beforehand, but I could not figure out, why?
BR
I think I have to rephrase my question: what´s better in 6.47.9 wifiwise than with 6.49.7 ?
Nothing we know about, and hardly related to TX power.
But everything after 6.47.9 is worse than 6.47.9.
No more details known beyond what is mentioned in the (incomplete and sketchy) ROS release notes.
Thanks jbl42!
My advice for using 6.47.9 has nothing to do with TX power.
The problem introduced after this version (as part of a fix for some imaginary problem found by students searching for potential things to write a paper about) is that the connection becomes flaky. I was using a hAP lite as an access point and had a program running that processes “real time audio” (a web browser connected to a WebSDR receiver site), and the audio becomes choppy. Every couple of seconds there is a short interruption.
I even was able to quantify it using this website: https://packetlosstest.com/
That allows you to send ping-like packets at a certain rate and graph how many get lost, and at what time.
You see a clear repeating pattern of packet loss when using a RouterOS version above 6.47.9
Since then I have replaced that hAP lite with a hAP ac2, that of course solves the problem too. But I would recommend not upgrade beyond 6.47.9, that security issue really is not a problem in practice.
I’ve installed 6.47.9 on my new hAP lite (using netinstall).
Factory/current firmware is 6.47.10 - newer than installed ROS. Could this be a problem? Looks like i cannot downgrade firmware, for good reason I assume.