Hudratores from 524wifi.com & wifi6.eu  how-to setup LTE / 4G / 5G modems on COMPEX router board:

Third, if you still fail to make it work, you can 1. shoot yourself 2. start crying or 3. refer to this article:

https://compexsystems.freshdesk.com/support/solutions/articles/36000164813  

pls if you don’t have access to Compex very sacred web manuals, all pictures are on the end starting by LTE Modules Configuration Steps

BUT, I tried to use some recommended mods to make modem works and I always returned to old good LTE / UMTS / GPRS / EV-DO protocol for simple reason, it works for all tested modems, yes ill show you which one is fastest, I know you want to see it (Quectel EC25E, EP06E ,Sierra EM7455). Oh, back to idea, I used this protocol because…… I need to connect to O2, Vodafone and T-Mobile here using not only APN: internet, but dial *99# as well, and that is impossible with other mods (and now you know another secret might help to make it work)

Readme for COMPEX v6.4.02_spf61_b200825 firmware for WPJ428 and WPJ563 boards :  test firmware to support Quectel EM12 modem

please use mbim protocol and /dev/cdc-wdm0 device for this modem

Use this command to show sim card iccid:
gcom -d /dev/ttyUSB2 -s /etc/gcom/geticcidq.gcom

Now probably your board and module and SIM works smoothly and you are dancing around the table celebrating , that your compex 419 board works and you know, it was worth it, because guys, this tested wpj419 board is smoking gun in compare to speeds , wifi load (who doesnt know compex profi wifi moduls right? ) and stability, and i have tested many LTE boards, believe me – you know what, ill put here simple measuring made at the table with samsung s9+ over wifi 5 ac  160width in my hand, voila:

BTW if you don’t read Czech (believe it or not, there may be still few uneducated readers out there ), note that left number is download, right number upload & …... this Sierra Wireless modem module is little devil isn’t it – Oh and for this modem we used adapter

Now is the time to clap your hands, say Thanks Hud and if necessary, to read boring files below. See ya at testing more expansive boards (when they give them to me)

Always yours (in love with Compex, Quectel, Sierra Wireless)

Hud & Dan from 524wifi.com email Daniel at 524wifi dot com

Compex stolen "how to" file follows, but i suggest you go to this page directly, as its dynamic and still evolving :

 https://compexsystems.freshdesk.com/support/solutions/articles/36000164813  

1. Before setup the Cellular Network, you may prompt to yourserverip/prod/info.txtto verify the LTE modules and SIM card was able to detect by Compex Embedded Board. Check on the USB LTE and LTE SIM column, you may able to see the information listed on each column.

1. Click Edit on WAN interface.

1. Choose NCM mode under protocol. 
2. Choose the SIM slot using. Depend on the SIM card is located on which port. If the board only have one SIM slot, it probably located at Slot 0. 
3. For Modem device, you are required to manually figure out the Modem device located on which interface. In this example
4. For Service type, you may choose your preferred operating mode such as LTE mode.
5. For IP protocol, you may choose it to allocate IP based on IPv4 format.    
6. At last, the cellular network is establish and now you may browse Internet by using Cellular Network, To verify the Internet connectivity, you may either setup AP on your wireless card and connected on the particular AP or you may notice the Internet Icon on top right side Light up.

1. Choose QMI Mode under protocol. 
2. Choose the SIM slot using. Depend on the SIM card located on which SIM slot. 
3. For Modem Device, you may choose either wdm0 or wdm1.
4. Ignore others column and proceed to Save & Apply.
5.  At last, the cellular network is established and now you may browse Internet by using Cellular Network,. To verify the Internet connectivity, you may either setup AP on your wireless card and connected on the particular AP or you may notice the Internet Icon on top right-side Light up.