Hi All
I’m having a poke around in an HD4-MBX which is the heart of our new Celldome product, and noticed on the support page there is a “Cellular Diagnostic Mode”.
What is this and how does it work?
As a possibly related question - now that the CAT18 modems have 4 connections per modem, what is the best way to test cables and antennas? obviously the RSSI and RSSQ values are only of limited value if you’re not able to use the particular cable and antenna. If there was some fast way within the Peplink to show closed or open connection on each antenna port, that would be good. Some sort of SWR test at target frequencies would be amazing
That’s what a vector network analyzer (VNA) is for. 
(They don’t cost so much any more.)
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Thanks for that Rick,
What I was kind of hoping for is some sort of method for doing this within the router, so that we could do some rough and ready trouble shooting remotely. Basically something which will allow us to at least say the connector has been ripped off the cable or the connector submerged in salt water. There’s a few AT commands for the LM960 which I think might be able to do something like this. Is there a way to access AT commands for each modem through the web interface?
While I’m at it, Do you (or anyone) have any VNA recommendations for technician use - must be portable enough to use on boats!
Hi @Horizon. Not sure about the commands for the LM960 – can’t help with that. I certainly understand your interest, however.
Our most portable VNA is the Nano (around US$100 +/-) which fits in a pocket, although we like to use it hooked to a laptop. You can still buy VNAs for US$10K+ (and we have one we paid richly for) but the new ones do pretty much the same thing. Not for the feint of heart, however. If one does not understand Smith charts, for example, just a little bit, a plain ol’ SWR bridge will be easier to use and interpret. Of course, you have to have a steady state emitter to use the latter. 
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(They don’t cost so much any more.)