I’m playing with a Knot and I’m trying to understand how to manage and access all the different modem GNSS/LTE info. However I am confused about the setting regarding data channel and info channel.
I couldn’t really find anything in the documentation.
For instance when I’m doing a interface/ppp-client/info ppp-out1 it works, but then when I try to come back to it I have “failure: can’t reuse data channel while ppp is running.”
Also, even following the knot page on how to switch from lte to gnss, I can’t get gnss data either. Again probably an error in my config on the gps for channel and init channel.
So I’ll appreciate a primer on the use of data and info channel. Thanks
If you use “/port/print” you’ll notice there are 5 channels on the USB bus.
So GPS (NMEA) uses channel 1, and “PPP data” uses channel 3 — those channels are used continuously so they cannot conflict.
Now, I think, by default, channel 2 is used by BOTH “PPP info” and “GPS init” — however, PPP info is ONLY used when use the “Info” button (or /interface ppp-client/info) & GPS is only use ONCE to setup modem. So ppp info and gps init likely shouldn’t conflict. I believe channel 4 is also AT, so that might be usable as the “ppp info” (but never tested it) if you’re worried about the conflict.
Also, if the modem is not working, you would see ERROR in the PPP info… it not showing ANYTHING or an error would indicate the port is wrong/active… so I’d check the APN in PPP you’re using to make sure that’s correct.
It looks like the ports are right, since both PPP and GPS are in use. If you look /system/gps, does it show a time as “Data Age”. If it’s showing 00:00:00 or :10 etc, instead of empty/none/etc
Do you have an antenna connected to the GNSS port? (I cannot recall if the KNOT has a internal antenna for GPS…)
And, yes, the docs could very much be improved. The manual is designed around RouterOS features, not devices… so for something like KNOT, all the docs for this are spread around in dozen pages.
But… nowhere would you find exactly what each serial channel does… There is a /system/serial-terminal that let’s you “test” them.
But FWIW info-channel=4 is NOT quite an LTE AT ports, so IDK if that work any better. In reality there should be no port conflict in PPP as long as the “data-channel” is not duplicated
LOL, yup. But the “info-channel” is not really used, unless you trigger it using “Info” — so I’m not sure that’s your issue with LTE. Essentially it sets up the PPP session using the “data-channel” so as long as that responds to AT commands in /system/serial-termial, it should work.
I’d really check the APN stuff to make sure that’s right for your SIM card. Often that why LTE does not work. If you have not updated to latest stable version (/system/package) and upgraded the fireware (/system/routerboard)… you might want to try that in case this is a bug in older versions.
Geez. The default should have been right. And the /system/default-configuration does NOT set any channel, so IDK what is the right default channels are… I actually tried deleting the ppp-out1 — since it should get re-created — but on my KNOT it actually does not come up after a reboot (normally ppp-out1 is added automatically)… So I cannot say what right (and not tested LTE on KNOT in a while)
If you’re running 7.18.2, you might try a ticket with Mikrotik at help.mikrotik.com
PPP interfaces are created only when RouterOS first time sees port, otherwise users will not be able to delete unneeded interfaces, because after reboot they will be recreated.
The problem is that the manual is wrong. They put there for the knot a data channel 2 and info channel 4. There is no channel 4 available on the knot…
I’m still having trouble with the knot and the script in the manual for getting gps fix when the ppp goes off.
After the 30s I see the On Down script executing, but immediately after, the ppp goes on again, despite not having requested any traffic on the ppp interface. I also checked that the ppp interface is not on the interface list for the neighbor discovery and that the keep alive is way above 30s.
Also I often have errors for the at chat command to switch the gps priority with an info channel already in use.
I’m so confused about these channels issue and there is no clear manual about them.
Same when you query info on the ppp, it works the first time, but you can’t get anymore info after that as it is already in use. And I can’t switch it off to query it again.
, although it subtle.