Configure And Use Ppp With A Digi Xbee 3 Cellular Lte-M/Nb-Iot Modem - Digi XBee 3 Cellular LTE-M User Manual

Modes
Note Although pin 6 is 5 V tolerant on this device, it operates with the same 3.3 V logic as the other
XBee device pins. For compatibility with other XBee devices we recommend driving the line with no
more than 3.3 V. Moreover, driving the pin at 5 V will cause input leakage current to increase to 3.3 µA
typical.
You must reset the device to enable or disable USB direct mode.
While in USB direct mode,
Configure and use PPP with a Digi XBee 3 Cellular LTE-M/NB-IoT
modem
Your XBee 3 Cellular device can communicate directly with the modem and can drop into PPP mode.
Prerequisites
A working SIM card to get onto the LTE-M network.
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Knowledge of the APN for the given network and SIM.
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A Linux distribution with pppd/chat.
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Step 1: Configure the device for PPP
USB direct is used to gain access to the underlying modem, which enables the use of PPP.
1. Set up USB direct
2. Issue the WR command
Once USB direct is configured, an additional USB device should be attached to the Linux machine. In
order to have a consistent device name on the Linux machine, you should set up a udev rule for the
device, as described in the next step.
Step 2: Set up the USB device for use with PPP
A udev rule is needed to give the USB connection a constant name using a symlink.
1. Make sure that the modem is plugged in.
2. Place the following ppp-setup.rules file here: /etc/udev/rules.d
# Sara-R410 rule
SUBSYSTEM=="tty", ATTRS{bInterfaceNumber}=="02", ENV{ID_VENDOR_ID}=="05c6", ENV{ID_
MODEL_ID}=="90b2", SYMLINK+="ppp_direct_usb"
3. You must run the two commands shown below to restart the udev daemon to apply the new
rule.
sudo udevadm control --reload-rules
sudo udevadm trigger
4. Verify that the new device has been created: /dev/ppp_direct_usb. If was not, make sure the
modem is plugged in and then repeat this process.
Step 3: Configure PPPD
PPPD by default looks in the /etc/ppp/ directory for an options file and a chat script. The option file
configures and specifies the chat script for PPPD. The chat script configures and dials the modem for
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide
AI (Association Indication)
mode.
to save the settings.
returns 0x2B.
USB direct mode
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