Digi XB3-C-A2-UT series User manual

Digi XBee3® Cellular LTE-M
Smart Modem
User Guide

Revision history—900002258
Revision Date Description
ADecember 2017 Initial release of the document.
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Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 2

Contents
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide
Applicable firmware and hardware 9
SIM cards 9
Getting started with the XBee Smart Modem Development Kit
Identify the kit contents 11
XBIB-U-DEV reference 12
Cellular service 13
Connect the hardware 14
Configure the device using XCTU 15
Add a device 15
Check for cellular registration and connection 16
Update to the latest firmware 16
Send an SMS message to a phone 18
Debugging 19
Connect to the ELIZA server 20
Debugging 21
Connect to the echo server 22
Debugging 23
Connect to the Daytime server 24
Debugging 25
Connect to a TCP/IP address 26
Debugging 27
Perform a (GET) HTTP request 28
Debugging 29
Get started with MQTT 30
Example: MQTT connect 30
Send a connect packet 32
Example: send messages (publish) with MQTT 34
Example: receive messages (subscribe) with MQTT 34
Use MQTT over the XBee Cellular Modem with a PC 35
Get started with CoAP 39
CoAP terms 39
CoAP quick start example 39
Configure the device 40
Example: manually perform a CoAPrequest 40
Example: use Python to generate a CoAP message 41
Configure the XBee Smart Modem using Digi Remote Manager 44
Create a Remote Manager account 44
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 3

Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 4
Get the XBee Smart Modem IMEI number 44
Add a XBee Smart Modem to Remote Manager 44
Update the firmware 45
Software libraries 45
Get started with MicroPython
About MicroPython 47
Why use MicroPython 47
MicroPython on the XBee Smart Modem 47
Use XCTU to enter the MicroPython environment 47
Use the MicroPython Terminal in XCTU 48
Example: hello world 48
Example: turn on an LED 48
Example: code a request help button 49
Enter MicroPython paste mode 50
Catch a button press 50
Send a text (SMS) when the button is pressed 52
Add the time the button was pressed 53
Exit MicroPython mode 54
Other terminal programs 54
Tera Term for Windows 54
Use picocom in Linux 55
Technical specifications
Interface and hardware specifications 58
Cellular RF characteristics 58
Bluetooth RF characteristics 58
Cellular Networking specifications 58
Power requirements 59
Power consumption 59
Electrical specifications 59
Regulatory approvals 60
Hardware
Mechanical drawings 62
Pin signals 62
Pin connection recommendations 64
RSSI PWM 64
SIM card 64
The Associate LED 65
Antenna recommendations
Antenna placement 67
Design recommendations
Power supply considerations 69
Minimum connection diagram 69

Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 5
Heat considerations and testing 69
Heat sink guidelines 71
Bolt-down style 71
Adhesive style heat sink 71
Add a fan to provide active cooling 72
Cellular connection process
Connecting 74
Cellular network 74
Data network connection 74
Data communication with remote servers (TCP/UDP) 74
Disconnecting 74
Modes
Select an operating mode 77
Transparent operating mode 78
API operating mode 78
Bypass operating mode 78
Enter Bypass operating mode 78
Leave Bypass operating mode 79
Restore cellular settings to default in Bypass operating mode 79
USB direct mode 79
Configure the data pins 79
Enable USB direct mode 79
Enable the VBUS option 80
Command mode 80
Enter Command mode 80
Send AT commands 81
Apply command changes 81
Make command changes permanent 81
Exit Command mode 82
Sleep modes
About sleep modes 84
Normal mode 84
Pin sleep mode 84
Cyclic sleep mode 84
Cyclic sleep with pin wake up mode 84
Airplane mode 84
SPI mode and sleep pin functionality 84
The sleep timer 85
MicroPython sleep behavior 85
Serial communication
Serial interface 88
Serial data 88
UART data flow 88
Serial buffers 89
CTS flow control 89

Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 6
RTS flow control 89
Enable UART or SPI ports 89
SPI operation
SPI communications 92
Full duplex operation 93
Low power operation 94
Select the SPI port 94
Force UART operation 95
Data format 95
AT commands
Special commands 97
AC (Apply Changes) 97
FR (Force Reset) 97
RE command 97
WR command 97
Cellular commands 98
PH (Phone Number) 98
S# (ICCID) 98
IM (IMEI) 98
MN (Operator) 98
MV (Modem Firmware Version) 99
DB (Cellular Signal Strength) 99
AN (Access Point Name) 99
AM (Airplane Mode) 99
Network commands 100
IP (IP Protocol) 100
TL (SSL/TLS Protocol Version) 100
TM (IP Client Connection Timeout) 100
TS (IP Server Connection Timeout) 101
DO (Device Options) 101
EQ (Device Cloud FQDN) 102
Addressing commands 102
SH (Serial Number High) 102
SL (Serial Number Low) 102
MY (Module IP Address) 102
P# (Destination Phone Number) 103
N1 (DNS Address) 103
N2 (DNS Address) 103
DL (Destination Address) 103
OD (Operating Destination Address) 104
DE (Destination Port) 104
C0 (Source Port) 104
LA (Lookup IP Address of FQDN) 105
Serial interfacing commands 105
BD (Baud Rate) 105
NB (Parity) 106
SB (Stop Bits) 106
RO (Packetization Timeout) 106
TD (Text Delimiter) 107
FT (Flow Control Threshold) 107

Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 7
AP (API Enable) 107
I/O settings commands 107
D0 (DIO0/AD0) 108
D1 (DIO1/AD1) 108
D2 (DIO2/AD2) 108
D3 (DIO3/AD3) 109
D4 (DIO4) 109
D5 (DIO5/ASSOCIATED_INDICATOR) 110
D6 (DIO6/RTS) 110
D7 (DIO7/CTS) 110
D8 (DIO8/SLEEP_REQUEST) 111
P0 (DIO10/PWM0 Configuration) 112
P1 (DIO11/PWM1 Configuration) 112
P2 (DIO12 Configuration) 113
P3 (DIO13/DOUT) 113
P4 (DIO14/DIN) 113
PD (Pull Direction) 114
PR (Pull-up/down Resistor Enable) 114
M0 (PWM0 Duty Cycle) 115
I/O sampling commands 115
TP (Temperature) 115
Sleep commands 116
SM (Sleep Mode) 116
SP (Sleep Period) 116
ST (Wake Time) 116
Command mode options 117
CC (Command Sequence Character) 117
CT (Command Mode Timeout) 117
GT (Guard Times) 117
MicroPython commands 117
PS (Python Startup) 118
PY (MicroPython Command) 118
Firmware version/information commands 119
VR (Firmware Version) 119
VL (Verbose Firmware Version) 119
HV (Hardware Version) 119
AI (Association Indication) 119
DI (Device Cloud Indicator) 120
CI (Protocol/Connection Indication) 120
HS (Hardware Series) 122
CK (Configuration CRC) 122
Execution commands 122
!R (Modem Reset) 122
IS (Force Sample) 123
Operate in API mode
API mode overview 125
Use the AP command to set the operation mode 125
API frame format 125
API operation (AP parameter = 1) 125
API operation with escaped characters (AP parameter = 2) 126
Frame descriptions 129
AT Command - 0x08 129
AT Command: Queue Parameter Value - 0x09 130

Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 8
Transmit (TX) Request: IPv4 - 0x20 131
AT Command Response - 0x88 132
Transmit (TX) Status - 0x89 133
Modem Status - 0x8A 134
Receive (RX) Packet: IPv4 - 0xB0 135
Socket behavior
Supported sockets 137
Socket timeouts 137
Socket limits in API mode 137
Enable incoming TCP sockets in API mode 137
API mode behavior for outgoing TCP and SSL connections 137
API mode behavior for outgoing UDP data 138
API mode behavior for incoming TCP connections 138
API mode behavior for incoming UDP data 139
Transparent mode behavior for outgoing TCP and SSL connections 139
Transparent mode behavior for outgoing UDP data 139
Transparent mode behavior for incoming TCP connections 140
Transparent mode behavior for incoming UDP connections 140
Troubleshooting
Cannot find the serial port for the device 142
Condition 142
Solution 142
Correct a macOS Java error 144
Condition 144
Solution 144
Unresponsive cellular component in Bypass mode 145
Condition 145
Solution 145
Syntax error at line 1 145
Solution 145
Network connection issues 145
Condition 145
Solution 145
Set the APN value 145
Regulatory information
United States (FCC) 148
OEM labeling requirements 148
FCC notices 148
FCC-approved antennas 149
RF exposure 150
IC (Industry Canada) 150
Labeling requirements 150
RF Exposure 150

Digi XBee3 Cellular LTE-M Global Smart Modem User
Guide
The XBee Smart Modem provides OEMs with a simple way to integrate low-power cellular connectivity
into their devices. Features include:
nFCC certified and carrier end-device certified
nExcellent coverage and building penetration
nDigi XBee Transparent and API modes simplify design
nLow power consumption optimized for long battery life
nReduced hardware complexity with only 1 antenna required
nIntegrated MicroPython programmability enables custom scripting directly on the modem
nEnhanced with Digi TrustFence™ security framework
nManage and configure with XCTU and Digi Remote Manager®
nAvailable with Digi provided SIM cards and data plans
Applicable firmware and hardware
This manual supports the following firmware:
n311xx
It supports the following hardware:
nXB3-C-A2-UT-xxx
SIM cards
The XBee Smart Modem requires a 4FF (Nano) size SIM card. The SIM interface supports both 1.8 V
and 3 V SIM types.
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 9

Getting started with the XBee Smart Modem
Development Kit
This section describes how to connect the hardware in the XBee Smart Modem Development Kit, and
provides some examples you can use to communicate with the device.
Identify the kit contents 11
XBIB-U-DEV reference 12
Cellular service 13
Connect the hardware 14
Configure the device using XCTU 15
Send an SMS message to a phone 18
Connect to the ELIZA server 20
Connect to the echo server 22
Connect to the Daytime server 24
Connect to a TCP/IP address 26
Perform a (GET) HTTP request 28
Get started with MQTT 30
Get started with CoAP 39
Configure the XBee Smart Modem using Digi Remote Manager 44
Software libraries 45
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 10

Getting started with the XBee Smart Modem Development Kit Identify the kit contents
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 11
Identify the kit contents
The Developer's kit includes the following:
One XBIB-U-DEV board
One 12 V power supply
One cellular antenna with U.FL connector
One Bluetooth Low Energy (BLE) antenna
(BLE support is forthcoming but not currently
available)
One USB cable
One XBee Smart Modem
One SIMcard

Getting started with the XBee Smart Modem Development Kit XBIB-U-DEV reference
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 12
XBIB-U-DEV reference
This picture shows the XBee USB development board and the table that follows explains the callouts
in the picture.
Number Item Description
1 Programmingheader Header used to program XBee Programmable devices.

Getting started with the XBee Smart Modem Development Kit Cellular service
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 13
Number Item Description
2 Self power module Advanced users only—voids the warranty. Depopulate R31 to
power the device using V+ and GND from J2 and J5. You can
connect sense lines to S+ and S- for sensing power supplies.
CAUTION: Voltage is not regulated. Applying the incorrect
voltage can cause fire and serious injury.1
3 Current testing Depopulating R31 allows a current probe to be inserted across P6
terminals. The current though P6/R31 powers the device only.
Other supporting circuitry is powered by a different trace.
4 Loopback jumper Populating P8 with a loopback jumper causes serial transmissions
both from the device and from the USB to loopback.
5 DC barrel plug: 6-20V Greater than 500 mA loads require a DC supply for correct
operation. Plug in the external power supply prior to the USB
connector to ensure that proper USB communications are not
interrupted.
6 LED indicator Yellow: Modem sending serial/UART data to host.
Green: Modem receiving serial/UART data from host.
Red: Associate.
7 USB
8 RSSI indicator
9 User buttons Connected to DIO lines for user implementation.
10 Reset button
11 SPI power Connect to the power board from 3.3 V.
12 SPI Only used for surface-mount devices.
13 Indicator LEDs DS5: ON/SLEEP
DS2: DIO12, the LED illuminates when driven low.
DS3: DIO11, the LED illuminates when driven low.
DS4: DIO4, the LED illuminates when driven low.
14 Through-hole XBee
sockets
15 20-pin header Maps to standard through-hole XBee pins.
Cellular service
The XBee Cellular kit includes six months of free cellular service.
1Powering the board with J2 and J5 without R31 removed can cause shorts if the USB or barrel plug power are
connected. Applying too high a voltage destroys electronic circuitry in the device and other board components
and/or can cause injury.

Getting started with the XBee Smart Modem Development Kit Connect the hardware
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 14
Connect the hardware
1. The XBee Smart Modem should already be plugged into the XBIB-U-DEV board.
2. The SIMcard should be already be inserted into the XBee Smart Modem. If not, install the
SIMcard into the XBee Smart Modem.
WARNING! Never insert or remove the SIM card while the device is powered!
3. Connect the antennas to the XBee Smart Modem by aligning the U.FL connectors carefully,
then firmly pressing straight down to seat the connector. You should hear a snap when the
antenna attaches correctly. U.FL is fragile and is not designed for multiple insertions, so
exercise caution when connecting or removing the antennas. We recommend using a U.FL
removal tool.
4. Plug the 12 V power supply to the power jack on the development board.
5. Connect the USB cable from a PC to the USB port on the development board. The computer
searches for a driver, which can take a few minutes to install.

Getting started with the XBee Smart Modem Development Kit Configure the device using XCTU
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 15
Configure the device using XCTU
XBee Configuration and Test Utility (XCTU) is a multi-platform program that enables users to interact
with Digi radio frequency (RF) devices through a graphical interface. The application includes built-in
tools that make it easy to set up, configure, and test Digi RF devices.
XCTU does not work directly over an SPI interface.
For instructions on downloading and using XCTU, see the XCTU User Guide.
Note If you are on a macOS computer and encounter problems installing XCTU, see Correct a macOS
Java error.
Add a device
These instructions show you how to add the XBee Smart Modem to XCTU. If XCTU does not find your
serial port, see Cannot find the serial port for the device.
1. Launch XCTU .
2. Click the Discover radio modules button .
3. In the Discover radio devices dialog, select the serial ports where you want to look for XBee
modules, and click Next.
4. In the Set port parameters window, maintain the default values and click Finish.
5. As XCTU locates radio modules, they appear in the Discovering radio modules dialog box.
If your module could not be found, XCTU displays the Could not find any radio module dialog
providing possible reasons why the module could not be added.

Getting started with the XBee Smart Modem Development Kit Configure the device using XCTU
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 16
Check for cellular registration and connection
In the following examples, proper cellular network registration and address assignment must occur
successfully. The LED on the development board blinks when the XBee Smart Modem is registered to
the cellular network; see The Associate LED. If the LEDremains solid, registration has not occurred
properly. Registration can take several minutes.
Note Make sure you are in an area with adequate cellular network reception or the XBee Smart
Modem will not make the connection.
In addition to the LED confirmation, you can check the AT commands below in XCTU to check the
registration and connection. To view these commands:
1. Open XCTU and Add a device.
2. Click the Configuration working mode button.
3. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
4. On the Configuration toolbar, click the Default button to load the default values
established by the firmware, and click Yes to confirm.
The relevant commands are:
nAI (Association Indication) reads zero when the device successfully registers to the cellular
network. If it reads 0x23 it is connecting to the Internet; 0x22 means it is registering to the
cellular network.
nMY (Module IPAddress) should display a valid IPaddress. If it reads 0.0.0.0, it has not
registered yet.
Note To search for an ATcommand in XCTU, use the search box.
Update to the latest firmware
Firmware is the program code stored in the device's persistent memory that provides the control
program for the device. Use XCTU to update the firmware.
1. Click the Configuration working modes button .
2. Select a local XBee module from the Radio Modules list.
3. Click the Update firmware button .
The Update firmware dialog displays the available and compatible firmware for the selected
XBee module.
4. Select the product family of the XBee module, the function set, and the latest firmware version.

Getting started with the XBee Smart Modem Development Kit Configure the device using XCTU
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 17
5. Click Update. A dialog displays update progress. Click Show details for details of the firmware
update process.
See How to update the firmware of your modules in the XCTU User Guide for more information.

Getting started with the XBee Smart Modem Development Kit Send an SMS message to a phone
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 18
Send an SMS message to a phone
The XBee Smart Modem can send and receive Short Message Service (SMS) transmissions (text
messages) while in Transparent mode. This allows you to send and receive text messages to and from
an SMS capable device such as a mobile phone.
The following table explains the AT commands that you use in this example.
Command Value Description
AP (APIEnable) 0 Set the device's API mode to Transparent mode.
IP (IP Protocol) 2 Set the expected transmission mode to SMScommunication.
P#
(DestinationPhone
Number)
<Target
phone
number>
The target phone number that you send to, for example, your
cellular phone. See P# (Destination Phone Number) for instructions
on using this command.
TD (Text Delimiter) D (0x0D) The text delimiter to be used for Transparent mode, as an ASCII hex
code. No information is sent until this character is entered, unless
the maximum number of characters has been reached. Set to zero
to disable text delimiter checking. Set to D for a carriage return.
PH (Module's SIM
phone number)
Read
only
The value that represents your device's phone number as supplied
by the SIM card. This is used to send text messages to the device
from another cellular device.
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode button.
4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To switch to SMS communication, in the IP field, select 2and click the Write button .
6. To enter your cell phone number, in the P# field, type the <target phone number> and click
the Write button. Type the phone number using only numbers, with no dashes. You can use the
+prefix if necessary. The target phone number is the phone number you wish to send a text to.
7. In the TD field, type Dand click the Write button.
8. Note the number in the PH field; it is the XBee Smart Modem phone number, which you see
when it sends an SMS to your phone.

Getting started with the XBee Smart Modem Development Kit Send an SMS message to a phone
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 19
9. Click the Consoles working mode button on the toolbar to open a serial console to the
device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.
10. Click the Open button to open a serial connection to the device.
11. Click in the left pane of the Console log, type hello world and press Enter. The XBee Smart
Modem sends the message to the destination phone number set by the P# command.
12. When the phone receives the text, you can see that the sender's phone number matches the
value reported by the XBee Smart Modem with the PH command.
13. On the phone, reply with the text connect with confidence and the XBee Smart Modem
outputs this reply from the UART.
Debugging
If you experience problems with the settings in this example, you can load the default settings in
XCTU:
1. On the Configuration toolbar, click the Default button to load the default values
established by the firmware, and click Yes to confirm.
2. Factory settings are loaded but not written to the device. To write them, click the Write button
on the toolbar.

Getting started with the XBee Smart Modem Development Kit Connect to the ELIZA server
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 20
Connect to the ELIZA server
You can use the XBee Smart Modem to chat with the ELIZA Therapist Bot. ELIZAis an artificial
intelligence (AI) bot that emulates a therapist and can perform simple conversations.
The following table explains the AT commands that you use in this example.
At command Value Description
IP (IP Protocol) 1 Set the expected transmission mode to TCP
communications.
DL (Destination
Address)
52.43.121.77 The target IP address of the Eliza server.
DE (Destination Port) 0x2328 The target port number of the Eliza server.
To communicate with the ELIZA Therapist Bot:
1. Ensure that the device is set up correctly with the SIM card installed and the antennas
connected as described in Connect the hardware.
2. Open XCTU and Add a device.
3. Click the Configuration working mode button.
4. Select a device from the Radio Modules list. XCTU displays the current firmware settings for
that device.
5. To switch to TCP communication, in the IP field, select 1 and click the Write button .
6. To enter the destination address of the ELIZATherapist Bot, in the DL field, type 52.43.121.77
and click the Write button.
7. To enter the destination IP port number, in the DE field, type 2328 and click the Write button.
8. Click the Consoles working mode button on the toolbar to open a serial console to the
device. For instructions on using the Console, see the AT console topic in the XCTU User Guide.
9. Click the Open button to open a serial connection to the device.
10. Click in the left pane of the Console log, then type in the Console to talk to the ELIZA Therapist
Bot. The following screenshot provides an example of this chat.