Digi XBee3 XB3M1, Руководство пользователя

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Troubleshooting Network connection issues
Digi XBee3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide 243
Network connection issues
Condition
The XBee Smart Modem is not joining the network, AI (Association Indication) is cycling between 0xFF
(Initalizing), 0x22 (Registering to Cellular Network) and 0x25 (Cellular Network Registration Denied).
Solution
Some things to check are:
n
The antennas are connected correctly to the device.
n
The SIM card is seated properly in the device.
n
APN is set correctly.
n
If you had to change a modem parameter, check to make sure you have reset the module
using the
FR command or by pressing the reset button, especially if you have changed settings
such as CP , N# , BM , or BN .
Note The default APN configured in the kit should allow the XBee Smart Modem to get on the network
with the SIM included in the kit. However, you may program the APN explicitly to 10569.mcs if you are
having difficulty registering with the network.
Brownout issue
The XBee3 RF Module uses a Silicon Labs EFR32MG System on Chip (SoC). Silicon Labs has announced
an intermittent restarting issue with EFR32MG revision B SoCs which can be caused by voltage
brownout or supply dips during power-on. The information below is provided to help you avoid this
condition.
Voltage brownout
This issue may occur if the supply powering the XBee VCC pin dips momentarily into the range of
approximately 1.2 to 1.8 V. When the supply returns to normal levels the SoC may not restart properly
and enter an unresponsive state. You must fully power cycle the XBee to recover from this state. The
failure rate tends to increase with slower ramp down rates of the power supply; for more details see
RMU_E203 — AVDD Ramp Issue . If you keep the power supply within the operational voltage range
specified in Power requirements , the conditions to cause this failure are never met.
Power-on discontinuities
This issue is similar to the voltage brownout issue. The SoC may fail to start if, during power on, the
supply powering the VCC pin experiences discontinuities in the voltage rise (in other words, dips) while
the voltage is in the range of approximately 1.2 to 1.8 V. You must fully power cycle the XBee Smart
Modem to recover from this state. The failure rate tends to increase with slower ramp up rates of the
power supply; for more details see
RMU_E203 — AVDD Ramp Issue . The issue can be avoided by
ramping your power supply steadily to the normal operating range.
How to distinguish revision B parts
Silicon Labs has corrected these issues in revision C of their SoC. We are printing the SoC revision on
the XBee label to make it easy to distinguish. The revision letter is located on the bottom right corner