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A port named "modem" is used for cellular connection (serial/PPP connection) and GNSS NMEA data: 

/port print     
Flags: I - INACTIVE
Columns: DEVICE, NAME, CHANNELS, USED-BY, BAUD-RATE
#   DEVICE  NAME    CHANNELS  USED-BY  BAUD-RATE
0           modbus         1                9600
1   1-1.4   modem          5              115200

Default modem port channel assignment:

1 - GNSS NMEA output port;

2 - AT/modem port;

4 - AT/modem port - KNOT LORA kits and KNOT with an internal USB hub.

Cellular configuration

Unlike LTE devices, the KNOT BG77 by default does not provide a direct IP modem interface (LTE interface), but provides AT/modem serial port which is used for serial/PPP connection. 

KNOT by default has a serial/PPP connection preset:

/interface ppp-client print
Flags: X - disabled; R - running 
 0 R  name="ppp-out1" max-mtu=1500 max-mru=1500 mrru=disabled port=modem 
      data-channel=2 info-channel=4 apn="internet" pin="" user="" password="" 
      profile=default phone="" dial-command="ATDT" 
      modem-init="AT+QGPSCFG="priority",1" null-modem=no dial-on-demand=yes 
      add-default-route=yes default-route-distance=1 use-peer-dns=yes 
      keepalive-timeout=30 allow=pap,chap,mschap1,mschap2                              

For more details on modem port configuration please see the KNOT port configuration/map above.

For more details on serial/PPP connection please check the link.

GNSS configuration

You can find more information by checking the guide here.

BG77 modem shares the same receiver for IoT cellular connectivity and GNSS signal reception. The preferred service can be prioritized by using the modem-init string (configured under /interface ppp-client) and GNSS service init-string (configured under /system gps).

AT priority commands are:

AT+QGPSCFG="priority",0 → to prioritize GNSS;
AT+QGPSCFG="priority",1 → to prioritize cellular IoT connectivity;

AT+QGPS=0 → to stop GNSS reception;
AT+QGPS=1 → to start GNSS reception.

Buttons and jumpers

Reset button

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