XBee/XBee-PRO S2C 802.15.4 Guide Datasheet by Digi

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DIGI.’
XBee/XBee-PRO S2C 802.15.4
Radio Frequency (RF) Module
User Guide
Revision history—90001500
Revision Date Description
G May 2018 Added note on range estimation. Changed ICto ISED.
H June 2018 Changes to the Active Scan command.
J May 2019 Removed Brazilian certification information.
K May 2019 Added FCC publication 996369 related information.
L July 2019 Added the NPcommand. Added RS-485 support.
Trademarks and copyright
Digi, Digi International, and the Digi logo are trademarks or registered trademarks in the United
States and other countries worldwide. All other trademarks mentioned in this document are the
property of their respective owners.
© 2018 Digi International Inc. All rights reserved.
Disclaimers
Information in this document is subject to change without notice and does not represent a
commitment on the part of Digi International. Digi provides this document “as is, without warranty of
any kind, expressed or implied, including, but not limited to, the implied warranties of fitness or
merchantability for a particular purpose. Digi may make improvements and/or changes in this manual
or in the product(s) and/or the program(s) described in this manual at any time.
Warranty
To view product warranty information, go to the following website:
www.digi.com/howtobuy/terms
Customer support
Gather support information: Before contacting Digi technical support for help, gather the following
information:
Product name and model
Product serial number (s)
Firmware version
Operating system/browser (if applicable)
Logs (from time of reported issue)
Trace (if possible)
Description of issue
Steps to reproduce
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 2
Contact Digi technical support: Digi offers multiple technical support plans and service packages.
Contact us at +1 952.912.3444 or visit us at www.digi.com/support.
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XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 3
Contents
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide
Applicable firmware and hardware 11
Technical specifications
Performance specifications 13
Power requirements 13
General specifications 14
Regulatory conformity summary 14
Serial communication specifications 15
UART pin assignments 15
SPI pin assignments 15
GPIO specifications 15
Hardware
Antenna options 18
Mechanical drawings 18
Mounting considerations 19
Pin signals 20
Notes 23
Design notes 23
Power supply design 23
Board layout 23
Antenna performance 23
Keepout area 24
RF pad version 26
Configure the XBee/XBee-PRO S2C 802.15.4 RF Module
Software libraries 30
Configure the device using XCTU 30
Over-the-air (OTA) firmware update 30
XBee Network Assistant 30
XBee Multi Programmer 31
Modes
Serial modes 33
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 4
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 5
Transparent operating mode 33
API operating mode 33
Command mode 34
Transceiver modes 36
Idle mode 36
Transmit mode 36
Receive mode 36
Operation
Addressing 38
Send packets to a specific device 38
Addressing modes 38
Encryption 38
Maximum payload 40
Maximum payload rules 40
Maximum payload summary tables 41
Work with Legacy devices 41
Networking 42
MAC Mode configuration 42
XBee retries configuration 43
Transmit status based on MAC mode and XBee retries configurations 43
Peer-to-peer networks 44
Master/slave networks 44
Clear Channel Assessment (CCA) 48
CCA operations 48
Serial interface 49
Select a serial port 49
UART data flow 50
Flow control 51
SPI operation 52
SPI signals 52
SPI parameters 53
SPI and API mode 53
Full duplex operation 54
Slave mode characteristics 54
I/O support 55
Digital I/O line support 56
Analog input 56
On demand I/O sampling 56
Periodic I/O sampling 58
Change Detect I/O sampling 59
Wakeup I/O sampling 60
Sample rate (interval) 60
I/O line passing 60
Output control 61
Sleep support 61
Sleep modes 61
Sleep parameters 62
Sleep current 63
Sleep pins 63
Direct and indirect transmission 63
Node discovery 64
Node discovery 64
Node discovery in compatibility mode 65
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 6
Directed node discovery 65
Directed node discovery in compatibility mode 65
Destination Node 65
Remote configuration commands 66
Send a remote command 66
Apply changes on remote devices 66
Remote command responses 66
AT commands
Special commands 68
WR (Write) 68
RE (Restore Defaults) 68
FR (Software Reset) 68
Networking and security commands 68
C8 (802.15.4 Compatibility) 68
CH (Operating Channel) 70
ID (Network ID) 70
DH (Destination Address High) 70
DL (Destination Address Low) 71
MY (Source Address) 71
SH (Serial Number High) 71
SL (Serial Number Low) 71
MM (MAC Mode) 72
RR (XBee Retries) 72
RN (Random Delay Slots) 73
ND (Network Discovery) 73
NT (Node Discover Timeout) 74
NO (Node Discovery Options) 74
DN (Discover Node) 75
CE (Coordinator Enable) 75
SC (Scan Channels) 76
SD (Scan Duration) 76
A1 (End Device Association) 77
A2 (Coordinator Association) 78
AI (Association Indication) 79
DA (Force Disassociation) 79
FP (Force Poll) 79
AS (Active Scan) 80
ED (Energy Detect) 81
EE (Encryption Enable) 81
KY (AES Encryption Key) 81
NI (Node Identifier) 82
NP command 82
RF interfacing commands 82
PL (TX Power Level) 83
PM (Power Mode) 84
CA (CCA Threshold) 84
Sleep commands 84
SM (Sleep Mode) 84
ST (Time before Sleep) 85
SP (Cyclic Sleep Period) 85
DP (Disassociated Cyclic Sleep Period) 86
SO (Sleep Options) 86
Serial interfacing commands 86
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 7
BD (Interface Data Rate) 87
NB (Parity) 88
RO (Packetization Timeout) 88
D7 (DIO7/CTS) 88
D6 (DIO6/RTS) 89
AP (API Enable) 89
I/O settings commands 90
D0 (DIO0/AD0) 90
D1 (DIO1/AD1) 90
D2 (DIO2/AD2) 91
D3 (DIO3/AD3) 91
D4 (DIO4) 92
D5 (DIO5/ASSOCIATED_INDICATOR) 92
D8 (DIO8/SLEEP_REQUEST) 93
P0 (RSSI/PWM0 Configuration) 93
P1 (PWM1 Configuration) 94
P2 (SPI_MISO) 94
M0 (PWM0 Duty Cycle) 95
M1 (PWM1 Duty Cycle) 95
P5 (SPI_MISO) 95
P6 (SPI_MOSI Configuration) 96
P7 (SPI_SSEL ) 96
P8 (SPI_SCLK) 96
P9 (SPI_ATTN) 97
PR (Pull-up/Down Resistor Enable) 97
PD (Pull Up/Down Direction) 98
IU (I/O Output Enable) 98
IT (Samples before TX) 98
IS (Force Sample) 99
IO (Digital Output Level) 99
IC (DIO Change Detect) 99
IR (Sample Rate) 100
RP (RSSI PWM Timer) 100
I/O line passing commands 100
IA (I/O Input Address) 101
T0 (D0 Timeout) 101
T1 (D1 Output Timeout) 101
T2 (D2 Output Timeout) 101
T3 (D3 Output Timeout) 102
T4 (D4 Output Timeout) 102
T5 (D5 Output Timeout) 102
T6 (D6 Output Timeout) 102
T7 (D7 Output Timeout) 102
PT (PWM Output Timeout) 103
Diagnostic commands 103
VR (Firmware Version) 103
VL (Version Long) 103
HV (Hardware Version) 103
DB (Last Packet RSSI) 104
EC (CCA Failures) 104
EA (ACK Failures) 104
DD (Device Type Identifier) 104
Command mode options 105
CT (Command mode Timeout) 105
CN (Exit Command mode) 105
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 8
AC (Apply Changes) 105
GT (Guard Times) 106
CC (Command Character) 106
Operate in API mode
API mode overview 108
API frame specifications 108
API operation (AP parameter = 1) 108
API operation-with escaped characters (AP parameter = 2) 108
Start delimiter 109
Length 109
Frame data 109
Checksum 110
Calculate and verify checksums 110
Escaped characters in API frames 111
Frame descriptions 112
TX Request: 64-bit address frame - 0x00 112
TX Request: 16-bit address - 0x01 113
AT Command frame - 0x08 114
AT Command - Queue Parameter Value frame - 0x09 116
Remote AT Command Request frame - 0x17 117
RX Packet: 64-bit Address frame - 0x80 118
Receive Packet: 16-bit address frame - 0x81 119
RX (Receive) Packet: 64-bit address IO frame- 0x82 120
RX Packet: 16-bit address I/O frame - 0x83 122
AT Command Response frame - 0x88 124
TX Status frame - 0x89 126
Modem Status frame - 0x8A 128
Remote Command Response frame - 0x97 129
Regulatory information
United States (FCC) 131
OEM labeling requirements 131
FCC notices 131
FCC-approved antennas (2.4 GHz) 133
RF exposure 145
FCC publication 996369 related information 145
Europe (CE) 146
Maximum power and frequency specifications 146
OEM labeling requirements 146
Listen Before Talk requirement 147
Declarations of conformity 147
Antennas 147
ISED (Innovation, Science and Economic Development Canada) 148
Labeling requirements 148
For XBee S2C surface-mount 148
For XBee-PRO S2C surface-mount 148
For XBee S2C through-hole 148
For XBee-PRO S2C through-hole 148
Transmitters for detachable antennas 148
Detachable antenna 149
Australia (RCM) 149
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 9
South Korea 149
Load 802.15.4 firmware on ZB devices
Background 155
Load 802.15.4 firmware 155
Migrate from XBee through-hole to surface-mount devices
Pin mapping 158
Mount the devices 159
PCB design and manufacturing
Recommended solder reflow cycle 162
Recommended footprint and keepout 162
Flux and cleaning 164
Rework 164
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide
XBee/XBee-PRO S2C 802.15.4 RF Modules are embedded solutions providing wireless end-point
connectivity to devices. These devices use the IEEE 802.15.4 networking protocol for fast point-to-
multipoint or peer-to-peer networking. They are designed for high-throughput applications requiring
low latency and predictable communication timing.
There are two footprints for the XBee/XBee-PRO S2C 802.15.4 RF Module hardware: through-hole
(TH) and surface-mount (SMT). TH devices include a 20-pin header and require the placement of two
1x10 sockets on the carrier board for mounting the device. SMT devices include 37 pads. They are
placed directly on the carrier board, which means they do not require holes or sockets for mounting.
The TH version may be useful for prototyping and production, but we recommend SMT for high-volume
applications, as the component can be placed automatically by a pick-and-place machine and you save
the cost of a socket on each board.
The XBee/XBee-PRO S2C 802.15.4 RF Module supports the needs of low-cost, low-power wireless
sensor networks. The devices require minimal power and provide reliable delivery of data between
devices. The devices operate within the ISM 2.4 GHz frequency band.
The XBee/XBee-PRO S2C 802.15.4 RF Module uses S2C hardware and the Silicon Labs EM357 chipset.
As the name suggests, the 802.15.4 module is over-the-air compatible with our Legacy 802.15.4
module (S1 hardware), and the TH versions of the new product are also form factor compatible with
designs that use the Legacy module.
Note OTA capability is only available when MM (Mac Mode)= 0 or 3
Applicable firmware and hardware 11
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 10
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide Applicable firmware and hardware
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 11
Applicable firmware and hardware
This manual supports the following firmware:
n802.15.4 version 20xx
It supports the following hardware:
nXB24C TH
nXB24C SMT
nXBP24C TH
nXBP24C SMT
Technical specifications
Performance specifications 13
Power requirements 13
General specifications 14
Regulatory conformity summary 14
Serial communication specifications 15
GPIO specifications 15
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 12
Technical specifications Performance specifications
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 13
Performance specifications
The following table describes the performance specifications for the devices.
Note Range figure estimates are based on free-air terrain with limited sources of interference. Actual
range will vary based on transmitting power, orientation of transmitter and receiver, height of
transmitting antenna, height of receiving antenna, weather conditions, interference sources in the
area, and terrain between receiver and transmitter, including indoor and outdoor structures such as
walls, trees, buildings, hills, and mountains.
Specification XBee value XBee-PRO value
Indoor / urban range Up to 200 ft (60 m) Up to 300 ft. (90 m)
Outdoor RF line-of-sight range Up to 4000 ft (1200 m) Up to 2 miles (3200
m)
Transmit power output (software
selectable)
6.3 mW (8 dBm), Boost mode1
3.1 mW (5 dBm), Normal mode
Channel 26 max power is 0.3 mW (-5
dBm)
63 mW (18 dBm)2
RF data rate 250,000 b/s 250,000 b/s
Maximum data throughput Up to 96,000 b/s Up to 96,000 b/s
UART interface data rate 1200 b/s to 250,000 b/s 1200 b/s to 250,000
b/s
SPI data rate Up to 5 Mb/s (burst) Up to 5 Mb/s (burst)
Receiver sensitivity -102 dBm, Boost mode
-100 dBm, Normal mode
-101 dBm
Power requirements
The following table describes the power requirements for the XBee/XBee-PRO S2C 802.15.4 RF
Module.
Specification XBee XBee-PRO
Supply voltage 2.1 - 3.6 V 2.7 - 3.6 V
Transmit current (typical, VCC = 3.3 V) 45 mA (8 dBm, Boost mode)
33 mA (5 dBm, Normal mode)
120 mA (18 dBm)
Idle / receive current (typical, VCC = 3.3 V) 31 mA (Boost mode)
28 mA (Normal mode)
31 mA
Power-down current <1 uA @ 25C <1 uA @ 25C
1Boost mode enabled by default; see PM (Power Mode).
2See Regulatory information for region-specific certification requirements.
Technical specifications General specifications
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 14
General specifications
The following table describes the general specifications for the devices.
Specification XBee XBee-PRO
Operating
frequency
ISM 2.4 GHz
Supported
channels
11 - 26 12 - 23
Form factor TH: 2.438 x 2.761 cm (0.960 x 1.087 in)
SMT: 2.199 x 3.4 x 0.305 cm (0.866 x
1.33 x 0.120 in)
TH: 2.438 x 3.294 cm (0.960 x 1.297 in)
SMT: 2.199 x 3.4 x 0.305 cm (0.866 x
1.33 x 0.120 in)
Operating
temperature
-40 to 85 ºC (industrial)
Antenna options TH: PCB antenna, U.FL connector, RPSMA connector, or integrated wire
SMT: RF pad, PCB antenna, or U.FL connector
Regulatory conformity summary
This table describes the agency approvals for the devices.
Country
XBee
(surface-mount)
XBee-
PRO
(surface-
mount)
XBee
(through-
hole)
XBee-PRO
(through-
hole)
United States (FCC Part 15.247) FCC ID:
MCQ-XBS2C
FCC ID:
MCQ-
PS2CSM
FCC ID:
MCQ-S2CTH
FCC ID:
MCQ-PS2CTH
Innovation, Science and Economic
Development Canada (ISED)
IC:
1846A-XBS2C
IC:
1846A-
PS2CSM
IC:
1846A-S2CTH
IC:
1846A-
PS2CTH
FCC/IC test transmit power
output range
-26 to +8dBm -0.7 to
+19.4
dBm
-26 to +8 dBm +1 to +19
dBm
Europe (CE) Yes - Yes -
Australia RCM RCM RCM RCM
Japan R201WW10215369 R210- 105563
South Korea MSIP-CRM-DIG-
XBee-S2C
MSIP-CRM-
DIG-XBee-S2C-
TH
RoHS Compliant
Technical specifications Serial communication specifications
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 15
Serial communication specifications
The XBee/XBee-PRO S2C 802.15.4 RF Module supports both Universal Asynchronous Receiver /
Transmitter (UART) and Serial Peripheral Interface (SPI)serial connections.
UART pin assignments
The SC1 (Serial Communication Port 1) of the Ember 357 is connected to the UART port. The following
table provides the UART pin assignments.
Specifications Module pin number
UART pins XBee (surface-mount) XBee (through-hole)
DOUT 3 2
DIN / CONFIG 4 3
CTS / DIO7 25 12
RTS / DIO6 29 16
SPI pin assignments
The SC2 (Serial Communication Port 2) of the Ember 357 is connected to the SPI port.
Specifications Module pin number
SPI pins XBee (surface-mount) XBee (through-hole)
SPI_SCLK 14 18
SPI_SSEL 15 17
SPI_MOSI 16 11
SPI_MISO 17 4
SPI_ATTN 12 19
GPIO specifications
XBee/XBee-PRO S2C 802.15.4 RF Modules have 15 General Purpose Input / Output (GPIO) ports
available. The exact list depends on the device configuration, as some GPIO pads are used for
purposes such as serial communication.
GPIO Electrical Specification Value
Low Schmitt switching threshold 0.42 - 0.5 x VCC
High Schmitt switching threshold 0.62 - 0.8 x VCC
Input current for logic 0 -0.5 µA
Technical specifications GPIO specifications
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 16
GPIO Electrical Specification Value
Input current for logic 1 0.5 µA
Input pull-up resistor value 29 kΩ
Input pull-down resistor value 29 kΩ
Output voltage for logic 0 0.18 x VCC
(maximum)
Output voltage for logic 1 0.82 x VCC
(minimum)
Output source/sink current for pad numbers 3, 4, 5, 10, 12, 14, 15, 16, 17, 25, 26,
28, 29, 30, and 32 on the SMT modules
4 mA
Output source/sink current for pin numbers 2, 3, 4, 9, 12, 13, 15, 16, 17, and 19 on
the TH modules
4 mA
Output source/sink current for pad numbers 7, 8, 24, 31, and 33 on the SMT
modules
8 mA
Output source/sink current for pin numbers 6, 7, 11, 18, and 20 on the TH modules 8 mA
Total output current (for GPIO pads) 40 mA
Hardware
Antenna options 18
Mechanical drawings 18
Mounting considerations 19
Pin signals 20
Design notes 23
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 17
(0‘17 J mm “ m rum ) r-mr (’NoMmAL 125“ V {'MnxxMuM 14a“ 1 , ' INCLUDES LABEL mm ous rum TOPVIEW SIDE wew BOTTOM VIEW 005 mm ) L33 A001 (
Hardware Antenna options
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 18
Antenna options
The ranges specified are typical for the integrated whip (1.5 dBi) and dipole (2.1 dBi) antennas. The
printed circuit board (PCB) antenna option provides advantages in its form factor; however, it typically
yields shorter range than the whip and dipole antenna options when transmitting outdoors. For more
information, see XBee and XBee-PRO OEM RF Module Antenna Considerations Application Note.
Mechanical drawings
The following mechanical drawings of the XBee/XBee-PRO S2C 802.15.4 RF Module show all
dimensions in inches. The first drawing shows the surface-mount device (antenna options not shown).
The following drawings show the standard (non-PRO) through-hole device.
mm "“3“ Pmu M/NNN » ii 0 nan in. 1,1 ‘nm RPSMA 'nJSA m: rum 1 ”3, Wire Whip PCB Antenna Hm! am 024 ‘ [nu\ [nm\ RPSMA inn! U.FL Wire Whip PCB Antenna
Hardware Mounting considerations
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 19
The following drawings show the XBee-PRO through-hole device.
Mounting considerations
We design the through-hole module to mount into a receptacle so that you do not have to solder the
module when you mount it to a board. The development kits may contain RS-232 and USB interface
boards that use two 20-pin receptacles to receive modules.
PIN 20 PIN1 m P 0- PIN 11 V m n. m PIN 10 PIN 11 PIN 1 m m P
Hardware Pin signals
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 20
The following illustration shows the module mounting into the receptacle on the RS-232 interface
board.
Century Interconnect and Samtec manufacture the 2 x 10 pin 2 mm spacing receptacles on Digi
development boards. Several other manufacturers provide comparable mounting solutions; we
currently use the following receptacles:
nThrough-hole single-row receptacles: Samtec part number: MMS-110-01-L-SV (or equivalent)
nSurface-mount double-row receptacles: Century Interconnect part number: CPRMSL20-D-0-1
(or equivalent)
nSurface-mount single-row receptacles: Samtec part number: SMM-110-02-SM-S
Note We recommend that you print an outline of the module on the board to indicate the
correct orientation for mounting the module.
Pin signals
The following image shows the pin numbers; it shows the device's top sides, the shields are on the
bottom.
The following table shows the pin assignments for the through-hole device. In the table, low-asserted
signals have a horizontal line above signal name.
Pin Name Direction Description
1 VCC - Power supply
lfifi D|03 DIOl/
Hardware Pin signals
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 21
Pin Name Direction Description
2 DOUT Output UART data out
3 DIN/CONFIG Input UART data In
4 SPI_MISO Output Serial Peripheral Interface (SPI) Data Out
5 RESET Input Module reset (reset pulse must be at least 200 ns). This must
be driven as an open drain/collector. The device drives this
line low when a reset occurs. Never drive this line high.
6 PWM0/RSSI
PWM
Output PWM output 0 / RX signal strength indicator
7 PWM1 Output PWM output 1
8 [Reserved] - Do not connect
9 DI8/SLEEP_
RQ/DTR
Input Pin sleep control line or digital input 8
10 GND - Ground
11 DIO4/SPI_MOSI Both Digital I/O 4 / SPI Data In
12 DIO7/CTS Both Digital I/O 7 / Clear-to-send flow control
13 ON/SLEEP Output Device sleep status indicator
14 VREF -Feature not supported on this device. Used on other XBee
devices for analog voltage reference.
15 DIO5/ASSOC Both Digital I/O 5 / Associated indicator
16 DIO6/RTS Both Digital I/O 6 / Request-to-send flow control
17 DIO3/AD3/SPI_
SSEL
Both Digital I/O 3 / Analog input 3 / SPI select
18 DIO2/AD2/SPI_
CLK
Both Digital I/O 2 / Analog input 2 / SPI clock
19 DIO1/AD1/SPI_
ATTN
Both Digital I/O 1 / Analog input 1 / SPIAttention
20 DIO0/AD0 Both Digital I/O 0 / Analog input 0
The following table shows the pin assignments for the surface-mount device.
Pin Name Direction Function
1 GND - Ground
2 VCC - Power supply
3 DOUT Output UART data out
SPI_
Hardware Pin signals
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 22
Pin Name Direction Function
4 DIN/CONFIG Input UART data in
5 [Reserved] Output Do not connect
6 RESET Input Module reset (reset pulse must be at least 200 ns).
This must be driven as an open drain/collector. The
device drives this line low when a reset occurs. Never
drive this line high.
7 PWM0/RSSI PWM Output PWM output 0 / RX signal strength indicator
8 PWM1 Output PWM output 1
9 [Reserved] - Do not connect
10 DI8/SLEEP_RQ/DTR Input Pin sleep control line or digital input 8
11 GND - Ground
12 SPI_
ATTN/BOOTMODE
Output SPIAttention. Do not tie low on reset.
13 GND - Ground
14 SPI_CLK Input SPI clock
15 SPI_SSEL Input SPI select
16 SPI_MOSI Input SPI Data In
17 SPI_MISO Output SPI Data Out
18 [Reserved] - Do not connect
19 [Reserved] - Do not connect
20 [Reserved] - Do not connect
21 [Reserved] - Do not connect
22 GND - Ground
23 [Reserved] - Do not connect
24 DIO4 Both Digital I/O 4
25 DIO7/CTS Both Digital I/O 7 / Clear-to-send flow control
26 ON/SLEEP Output Device sleep status indicator
27 VREF -Feature not supported on this device. Used on other
XBee devices for analog voltage reference.
28 DIO5/ASSOC Both Digital I/O 5 / Associated indicator
29 DIO6/RTS Both Digital I/O 6 / Request-to-send flow control
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 23
Pin Name Direction Function
30 DIO3/AD3 Both Digital I/O 3 / Analog input 3
31 DIO2/AD2 Both Digital I/O 2 / Analog input 2
32 DIO1/AD1 Both Digital I/O 1 / Analog input 1
33 DIO0/AD0 Both Digital I/O 0 / Analog input 0
34 [Reserved] - Do not connect
35 GND - Ground
36 RF Both RF connection
37 [Reserved] - Do not connect
Notes
Minimum connections: VCC, GND, DOUT and DIN.
Minimum connections for updating firmware: VCC, GND, DIN, DOUT, RTS and DTR.
The table specifies signal direction with respect to the device.
The device includes a 50 kΩpull-up resistor attached to RESET.
Use the PR (Pull-up/Down Resistor Enable) command to configure several of the input pull-ups.
You can connect other pins to external circuitry for convenience of operation including the Associate
LED pin (pin 15). The Associate LED flashes differently depending on the state of the device.
Leave any unused pins disconnected.
Design notes
The following guidelines help to ensure a robust design.
Power supply design
A poor power supply can lead to poor device performance, especially if you do not keep the supply
voltage within tolerance or if it is excessively noisy. To help reduce noise, place a 1.0 μF and 8.2 pF
capacitor as near as possible to pin 1 on the PCB. If you are using a switching regulator for the power
supply, switch the frequencies above 500 kHz. Limit the power supply ripple to a maximum 100 mV
peak to peak.
Board layout
We design XBee devices to be self sufficient and have minimal sensitivity to nearby processors,
crystals or other printed circuit board (PCB) components. Keep power and ground traces thicker than
signal traces and make sure that they are able to comfortably support the maximum current
specifications. There are no other special PCB design considerations to integrate XBee devices, with
the exception of antennas.
Antenna performance
Antenna location is important for optimal performance. The following suggestions help you achieve
optimal antenna performance. Point the antenna up vertically (upright). Antennas radiate and receive
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 24
the best signal perpendicular to the direction they point, so a vertical antenna's omnidirectional
radiation pattern is strongest across the horizon.
Position the antennas away from metal objects whenever possible. Metal objects between the
transmitter and receiver can block the radiation path or reduce the transmission distance. Objects
that are often overlooked include:
nmetal poles
nmetal studs
nstructure beams
nconcrete, which is usually reinforced with metal rods
If you place the device inside a metal enclosure, use an external antenna. Common objects that have
metal enclosures include:
nvehicles
nelevators
nventilation ducts
nrefrigerators
nmicrowave ovens
nbatteries
ntall electrolytic capacitors
Do not place XBee devices with the chip or integrated PCB antenna inside a metal enclosure.
Do not place any ground planes or metal objects above or below the antenna.
For the best results, mount the device at the edge of the host PCB. Ensure that the ground, power,
and signal planes are vacant immediately below the antenna section.
Keepout area
We recommend that you allow a “keepout area, which the following drawings show.
Mwmmum KsepDuKArea mm was \ayers) as snnn F 3300Thou Keepout Area Nu meta‘ m keepouton an layers 1a 1mm [worm 140mm aanrnuu km 6mm XBee form hum r XBee PROhrm (actor Recommended KeapomAvea (AH pcalayem 1118mm Keepout Area ND new n mom an W; E E ‘ Pyernnededgenwra ” ' ” Fr . whenpusslble,keepmoduledosew 2 E sdgenflmavd 35mm The antenna pertonnance mwrovej Wm a larger keepout area
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 25
Through-hole keepout
Notes
1. We recommend non-metal enclosures. For metal enclosures, use an external antenna.
2. Keep metal chassis or mounting structures in the keepout area at least 2.54 cm (1 in) from the
antenna.
3. Maximize the distance between the antenna and metal objects that might be mounted in the
keepout area.
4. These keepout area guidelines do not apply for wire whip antennas or external RFconnectors.
Wire whip antennas radiate best over the center of a ground plane.
[m1 M r‘m‘um Keepum Risa for was AMeWa (A x mm: as rm“ F asaurrou Keepout Area Na velahnkeepumuna‘ my“ Lwrmtedvuunrgwspe'wned rmum,smasmrnemrgpm aw, mom anPvev, Gmund pom ave m vsmwmmdec w um a'ea Renommsflde KPepmMNEa rm was A'Hm'va \AH laye'S; ,J m- w warm 1 Nc 'v‘e‘al m keepautufl a1 Kaye's Keepout Area E g E K x 1 Prelined edge u! pca “—7 7 When Dosswble, keep meme c use to :g ecgeaihnard 2 ES 25 Sr m ww r T16 amm pP’fiu'maflce \mprnve: W a lavgsv keeawk arsa
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 26
Surface-mount keepout
RF pad version
The RF pad is a soldered antenna connection on the surface-mount device. The RF signal travels from
pin 36 on the module to the antenna through a single ended RF transmission line on the PCB. This line
should have a controlled impedance of 50 Ω.
For the transmission line, we recommend either a microstrip or coplanar waveguide trace on the PCB.
We provide a microstrip example below, because it is simpler to design and generally requires less
area on the host PCB than coplanar waveguide.
We do not recommend using a stripline RF trace because that requires routing the RF trace to an
inner PCB layer, and via transitions can introduce matching and performance problems.
The following figure shows a layout example of a microstrip connecting an RF pad module to a
through-hole RPSMA RF connector.
nThe top two layers of the PCB have a controlled thickness dielectric material in between. The
second layer has a ground plane which runs underneath the entire RF pad area. This ground
plane is a distance d, the thickness of the dielectric, below the top layer.
PCB LAYER | PCB LAYERZ
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 27
nThe top layer has an RF trace running from pin 36 of the device to the RF pin of the RPSMA
connector. The RF trace's width determines the impedance of the transmission line with
relation to the ground plane. Many online tools can estimate this value, although you should
consult the PCB manufacturer for the exact width. Assuming d= 0.025 in, and that the
dielectric has a relative permittivity of 4.4, the width in this example will be approximately
0.045 in for a 50 Ωtrace. This trace width is a good fit with the module footprint's 0.060 in pad
width.
We do not recommend using a trace wider than the pad width, and using a very narrow trace can
cause unwanted RF loss. You can minimize the length of the trace by placing the RPSMA jack close to
the module. All of the grounds on the jack and the module are connected to the ground planes directly
or through closely placed vias. Space any ground fill on the top layer at least twice the distance d(in
this case, at least 0.050 in) from the microstrip to minimize their interaction.
Number Description
1XBee surface-mount pin 36
2 50 Ωmicrostrip trace
3 Back off ground fill at least twice the distance between layers 1 and 2
Hardware Design notes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 28
Number Description
4 RF connector
5 Stitch vias near the edges of the ground plane
6 Pour a solid ground plane under the RF trace on the reference layer
Implementing these design suggestions helps ensure that the RFpad device performs to
specifications.
Configure the XBee/XBee-PRO S2C 802.15.4 RF
Module
Software libraries 30
Configure the device using XCTU 30
Over-the-air (OTA) firmware update 30
XBee Network Assistant 30
XBee Multi Programmer 31
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 29
Configure the XBee/XBee-PRO S2C 802.15.4 RF Module Software libraries
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 30
Software libraries
One way to communicate with the XBee/XBee-PRO S2C 802.15.4 RF Module is by using a software
library. The libraries available for use with the XBee/XBee-PRO S2C 802.15.4 RF Module include:
nXBee Java library
nXBee Python library
The XBee Java Library is a Java API. The package includes the XBee library, its source code and a
collection of samples that help you develop Java applications to communicate with your XBee devices.
The XBee Python Library is a Python API that dramatically reduces the time to market of XBee
projects developed in Python and facilitates the development of these types of applications, making it
an easy process.
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.
For instructions on downloading and using XCTU, see the XCTU User Guide.
Click Discover devices and follow the instructions. XCTU should discover the connected XBee/XBee-
PRO S2C 802.15.4 RF Modules using the provided settings.
Click Add selected devices.The devices appear in the Radio Modules list. You can click a module to
view and configure its individual settings. For more information on these items, see AT commands.
Over-the-air (OTA) firmware update
The XBee/XBee-PRO S2C 802.15.4 RF Module supports OTA firmware updates using XCTU version
6.3.0 or higher. For instructions on performing an OTAfirmware update with XCTU, see How to update
the firmware of your modules in the XCTU User Guide.
OTA capability is only available when MM (Mac Mode)= 0 or 3
XBee Network Assistant
The XBee Network Assistant is an application designed to inspect and manage RF networks created
by Digi XBee devices. Features include:
nJoin and inspect any nearby XBee network to get detailed information about all the nodes it
contains.
nUpdate the configuration of all the nodes of the network, specific groups, or single devices
based on configuration profiles.
nGeo-locate your network devices or place them in custom maps and get information about the
connections between them.
nExport the network you are inspecting and import it later to continue working or work offline.
nUse automatic application updates to keep you up to date with the latest version of the tool.
See the XBee Network Assistant User Guide for more information.
To install the XBee Network Assistant:
Configure the XBee/XBee-PRO S2C 802.15.4 RF Module XBee Multi Programmer
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 31
1. Navigate to digi.com/xbeenetworkassistant.
2. Click General Diagnostics, Utilities and MIBs.
3. Click the XBee Network Assistant - Windows x86 link.
4. When the file finishes downloading, run the executable file and follow the steps in the XBee
Network Assistant Setup Wizard.
XBee Multi Programmer
The XBee Multi Programmer is a combination of hardware and software that enables partners and
distributors to program multiple Digi Radio frequency (RF) devices simultaneously. It provides a fast
and easy way to prepare devices for distribution or large networks deployment.
The XBee Multi Programmer board is an enclosed hardware component that allows you to program up
to six RF modules thanks to its six external XBee sockets. The XBee Multi Programmer application
communicates with the boards and allows you to set up and execute programming sessions. Some of
the features include:
nEach XBee Multi Programmer board allows you to program up to six devices simultaneously.
Connect more boards to increase the programming concurrency.
nDifferent board variants cover all the XBee form factors to program almost any Digi RF device.
Download the XBee Multi Programmer application from:digi.com/support/productdetail?pid=5641
See the XBee Multi Programmer User Guide for more information.
Modes
Serial modes 33
Transceiver modes 36
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 32
Modes Serial modes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 33
Serial modes
The firmware operates in several different modes. Two top-level modes establish how the device
communicates with other devices through its serial interface: Transparent operating mode and API
operating mode. Use the AP command to choose Serial mode. XBee/XBee-PRO S2C 802.15.4 RF
Modules use Transparent operation as the default serial mode.
The following modes describe how the serial port sends and receives data.
Transparent operating mode
Devices operate in this mode by default. The device acts as a serial line replacement when it is in
Transparent operating mode. The device queues all UART data it receives through the DIN pin for RF
transmission. When a device receives RF data, it sends the data out through the DOUT pin. You can set
the configuration parameters using Command mode.
Note Transparent operating mode is not available when using the SPI interface; see SPI operation.
The device buffers data in the serial receive buffer until one of the following causes the data to be
packetized and transmitted:
nThe device receives no serial characters for the amount of time determined by the RO
(Packetization Timeout) parameter. If RO = 0, packetization begins when a character is
received.
nThe device receives the Command Mode Sequence (GT +CC +GT). Any character buffered in
the serial receive buffer before the sequence is transmitted.
nThe device receives the maximum number of characters that fits in an RF packet (100 bytes).
Serial-to-RF packetization
Data is buffered in the DI buffer until one of the following causes the data to be packetized and
transmitted:
1. No serial characters are received for the amount of time determined by the RO (Packetization
Timeout) parameter. If RO = 0, packetization begins when a character is received.
2. The maximum number of characters that will fit in an RF packet (100) is received. The
maximum payload depends on whether you use Compatibility mode or not. If you use it, the
maximum payload is 100 characters, but if you do not use it, depending on encryption, the App
header and addressing, the payload can be larger.
3. The Command Mode Sequence (GT +CC +GT) is received. Any character buffered in the DI
buffer before the sequence is transmitted.
If the device cannot immediately transmit (for instance, if it is already receiving RF data), the serial
data is stored in the DI Buffer. The data is packetized and sent at any RO timeout or when 100 bytes
(maximum packet size without Compatibility mode) are received.
If the DI buffer becomes full, hardware flow control must be implemented in order to prevent overflow
(loss of data between the host and device).
API operating mode
Application programming interface (API) operating mode is an alternative to Transparent mode. It is
helpful in managing larger networks and is more appropriate for performing tasks such as collecting
data from multiple locations or controlling multiple devices remotely. API mode is a frame-based
Modes Serial modes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 34
protocol that allows you to direct data on a packet basis. It can be particularly useful in large
networks where you need control over the operation of the radio network or when you need to know
which node a data packet is from. The device communicates UART or SPI data in packets, also known
as API frames. This mode allows for structured communications with serial devices.
For more information, see API mode overview.
Command mode
Command mode is a state in which the firmware interprets incoming characters as commands. It
allows you to modify the device’s configuration using parameters you can set using AT
commands.When you want to read or set any parameter of the XBee/XBee-PRO S2C 802.15.4 RF
Module using this mode, you have to send an AT command.Every AT command starts with the
lettersATfollowed by the two characters that identify the command and then by some optional
configuration values.
The operating modes of the XBee/XBee-PRO S2C 802.15.4 RF Module are controlled by the AP (API
Enable) setting, butCommand mode is always available as a mode thedevice can enter while
configured for any of the operating modes.
Command mode is available on the UART interface for all operating modes. You cannot use the SPI
interface to enter Command mode.
Enter Command mode
To get a device to switch into Command mode, you must issue the following sequence:+++within one
second. There must be at least one second preceding and following the+++sequence. Both the
command character (CC) and the silence before and after the sequence (GT) are configurable. When
the entrance criteria are met the device responds with OK\r on UART signifying that it has entered
Command mode successfully and is ready to start processing AT commands.
If configured to operate in Transparent operating mode, when entering Command mode the
XBee/XBee-PRO S2C 802.15.4 RF Module knows to stop sending data and start accepting commands
locally.
Note Do not press Return or Enter after typing+++because it interrupts the guard time silence and
prevents you from entering Command mode.
When the device is in Command mode, it listens for user input and is able to receive AT commands on
the UART. IfCTtime (default is 10 seconds) passes without any user input, the device drops out of
Command mode and returns to the previous operating mode. You can force the device to leave
Command mode by sending CN (Exit Command mode).
You can customize the command character, the guard times and the timeout in the device’s
configuration settings. For more information, seeCC (Command Character),CT (Command mode
Timeout)andGT (Guard Times).
Troubleshooting
Failure to enter Command mode is often due to baud rate mismatch. Ensure that the baud rate of the
connection matches the baud rate of the device. By default, BD (Interface Data Rate) =3(9600 b/s).
There are two alternative ways to enter Command mode:
nA serial break for six seconds enters Command mode. You can issue the "break" command
from a serial console, it is often a button or menu item.
nAsserting DIN (serial break) upon power up or reset enters Command mode. XCTU guides you
through a reset and automatically issues the break when needed.
“AT” + ASCII + Space + Parameter + Carriage prefix command (optional) (optional, HEX) return IIJJ—hl—l | Example: AT NI 2
Modes Serial modes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 35
Both of these methods temporarily set the device's baud rate to 9600 and return anOKon the UART
to indicate that Command mode is active. When Command mode exits, the device returns to normal
operation at the baud rate that BDis set to.
Send AT commands
Once the device enters Command mode, use the syntax in the following figure to send AT commands.
Every AT command starts with the lettersAT, which stands for "attention." TheATis followed by two
characters that indicate which command is being issued, then by some optional configuration values.
To read a parameter value stored in the device’s register, omit the parameter field.
The preceding example changes NI (Node Identifier) to My XBee.
Multiple AT commands
You can send multiple AT commands at a time when they are separated by a comma in Command
mode; for example,ATNIMy XBee,AC<cr>.
The preceding example changes theNI (Node Identifier) to My XBeeand makes the setting active
through AC (Apply Changes).
Parameter format
Refer to the list of AT commands for the format of individual AT command parameters. Valid formats
for hexidecimal values include with or without a leading0xfor exampleFFFFor0xFFFF.
Response to AT commands
When using AT commands to set parameters the XBee/XBee-PRO S2C 802.15.4 RF Module responds
with OK<cr> if successful and ERROR<cr> if not.
For devices with a file system:
ATAP1<cr>
OK<cr>
When reading parameters, the device returns the current parameter value instead of anOKmessage.
ATAP<cr>
1<cr>
Apply command changes
Any changes you make to the configuration command registers using AT commands do not take effect
until you apply the changes. For example, if you send theBDcommand to change the baud rate, the
actual baud rate does not change until you apply the changes. To apply changes:
1. Send AC (Apply Changes).
2. Send WR (Write).
or:
3. Exit Command mode.
Modes Transceiver modes
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 36
Make command changes permanent
Send a WR (Write) command to save the changes. WR writes parameter values to non-volatile memory
so that parameter modifications persist through subsequent resets.
Send as RE (Restore Defaults) to wipe settings saved using WR back to their factory defaults.
Note You still have to use WR to save the changes enacted with RE.
Exit Command mode
1. Send CN (Exit Command mode) followed by a carriage return.
or:
2. If the device does not receive any valid AT commands within the time specified byCT
(Command mode Timeout), it returns to Transparent or API mode. The default Command mode
timeout is10seconds.
For an example of programming the device using AT Commands and descriptions of each configurable
parameter, see AT commands.
Transceiver modes
The following modes describe how the transceiver sends and receives over-the-air (OTA) data.
Idle mode
When not receiving or transmitting data, the device is in Idle mode. During Idle mode, the device
listens for valid data on both the RF and serial ports.
Transmit mode
Transmit mode is the mode in which the device is transmitting data. This typically happens when data
is received from the serial port.
Receive mode
This is the default mode for the XBee/XBee-PRO S2C 802.15.4 RF Module. The device is in Receive
mode when it is not transmitting data. If a destination node receives a valid RF packet, the
destination node transfers the data to its serial transmit buffer.
Operation
Addressing 38
Encryption 38
Maximum payload 40
Networking 42
Clear Channel Assessment (CCA) 48
Serial interface 49
SPI operation 52
I/O support 55
Sleep support 61
Node discovery 64
Remote configuration commands 66
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 37
Operation Addressing
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 38
Addressing
Every RF data packet sent over-the-air contains a Source Address and Destination Address field in its
header. The XBee/XBee-PRO S2C 802.15.4 RF Module conforms to the 802.15.4 specification and
supports both short 16-bit addresses and long 64-bit addresses. A unique 64-bit IEEE source address is
assigned at the factory and can be read with the SL (Serial Number Low) and SH (Serial Number High)
commands. You must manually configure short addressing. A device uses its unique 64-bit address as
its Source Address if its MY (16-bit Source Address) value is 0xFFFF or 0xFFFE.
Send packets to a specific device
To send a packet to a specific device using 64-bit addressing:
nSet the Destination Address (DL +DH) of the sender to match the Source Address (SL +SH) of
the intended destination device.
To send a packet to a specific device using 16-bit addressing:
1. Set the DL parameter to equal the MY parameter of the intended destination device.
2. Set the DH parameter to 0.
Addressing modes
802.15.4 frames have a source address, a destination address, and a destination PAN ID in the over-
the-air (OTA) frame. The source and destination addresses may be either long or short and the
destination address may be either a unicast or a broadcast. The destination PAN ID is short and it may
also be the broadcast PAN ID.
In Transparent mode, the destination address is set by the DH and DL parameters, but, in API mode, it
is set by the TX Request:64-bit address (0x00) or TX Request: 16-bit Address (0x01) frames. In either
Transparent mode or API mode, the destination PAN ID is set with the ID parameter, and the source
address is set with the MY parameter.
Broadcasts and unicasts
Broadcasts are identified by the 16-bit short address of 0xFFFF. Any other destination address is
considered a unicast and is a candidate for acknowledgments, if enabled.
Broadcast PAN ID
The Broadcast PAN ID is also 0xFFFF. Its effect is to traverse all PANs in the vicinity. Typically, this only
makes sense during association time when sending beacon requests to find PAN IDs.
Short and long addresses
A short address is 16 bits and a long address is 64 bits. The short address is set with the MY
parameter. If the short address is 0xFFFE or 0xFFFF, then the address of the device is long and it is
the serial number of the device as read by the SH and SL parameters.
Note When an end device associates to a coordinator, it is assigned the short address of 0xFFFE.
Encryption
The XBee/XBee-PRO S2C 802.15.4 RF Module supports AES 128-bit encryption. 128-bit encryption
refers to the length of the encryption key entered with the KY command (128 bits = 16 bytes). The
Operation Encryption
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 39
802.15.4 protocol specifies eight security modes, enumerated as shown in the following table.
Level Name Encrypted?
Length of message integrity
check
Packet length
overhead
0 N/A No 0 (no check) 0
1 MIC-32 No 4 9
2 MIC-64 No 8 13
3 MIC-128 No 16 21
4 ENC Yes 0 (no check) 5
5 ENC-MIC-32 Yes 4 9
6 ENC-MIC-64 Yes 8 13
7 ENC-MIC-128 Yes 16 21
The XBee/XBee-PRO S2C 802.15.4 RF Module only supports security levels 0 and 4. It does not support
message integrity checks. EE 0 selects security level 0 and EE 1 selects security level 4. When using
encryption, all devices in the network must use the same 16-byte encryption key for valid data to get
through. Mismatched keys will corrupt the data output on the receiving device. Mismatched EE
parameters will prevent the receiving device from outputting received data.
Working from a maximum packet size of 116 bytes, encryption affects the maximum payload as shown
in the following table.
Factor
Effect on
maximum
payload Comment
Compatibility
mode
Force to 95 If C8 bit 0 is set, all packets are limited to 95 bytes, regardless of other
factors listed below. This is how the Legacy 802.15.4 module (S1
hardware) functions.
Packet
overhead
Reduce by 5 This penalty for enabling encryption is unavoidable due to the 802.15.4
protocol.
Source
address
Reduce by 6 This penalty is unavoidable because the 802.15.4 requires encrypted
packets to be sent with a long source address, even if a short address
would otherwise be used.
Destination
address
Reduce by 6 This penalty only applies if sending to a long address rather than a
short address.
App header Reduce by 4 The app header for encryption is 4 bytes long. This penalty only applies
if MM = 0 or 3.
Because of the two mandatory reductions when using encryption, no packet can exceed 116 - (5+6)
=105 bytes. The other options may further reduce the maximum payload to 101 bytes, 99 bytes, or 95
bytes.
When operating in API mode and not using encryption, if the source address is long, the receiving
device outputs an RX Indicator (0x80) frame for received data. But, if the source address is short, the
Operation Maximum payload
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 40
receiving device outputs a Receive Packet (0x81) frame for received data. These same rules apply for
encryption if MM is 0 or 3. This is possible because the four-byte encryption App header includes the
short address of the sender and the long received address is not used for API output. If encryption is
enabled with MM of 1 or 2, then no App header exists, the source address is always long, and the
receiving device in API mode always outputs a RX Packet: 64-bit Address frame - 0x80.
Maximum payload
There is a maximum payload that you can send at one time, depending on the device's configuration.
These maximums only apply in API mode. If you attempt to send an API packet with a larger payload
than specified, the device responds with a Transmit Status frame (0x89) with the Status field set to 74
(Data payload too large).
In Transparent mode, the firmware splits the data as necessary to cope with maximum payloads.
Maximum payload rules
Note Refer to NP command which can provide maximum packet size, it always assumes a long
destination address. This means that if you select a short destination address, you will be able to send
up to NP + 6 bytes in a single packet.
1. If you enable transmit compatibility with the Legacy 802.15.4 module (S1 hardware):
lThere is a fixed maximum payload of 100 bytes if not using encryption
lThere is a fixed maximum payload of 95 bytes if using encryption
lThe rest of the rules do not apply. They apply only whenyou disable transmit
compatibility with the Legacy 802.15.4 module.
2. The maximum achievable payload is 116 bytes. This is achieved when:
nNot using encryption.
nNot using the application header.
nUsing the short source address.
nUsing the short destination address.
3. If you are usingthe application header (MM (MAC Mode)set to 0or 3), the maximum achievable
payload is reduced by:
n2 bytes if not using encryption.
n4 bytes if using encryption.
4. If you are using the long source address,the maximum achievable payload is reduced by 6
bytes (size of long address (8) - size of short address (2) = 6).
5. If you are using encryption, the short source addresses are promoted to long source
addresses, sothe maximum achievable payload is reduced by 6 bytes.
6. If you are using the long destination address,the maximum achievable payload is reduced by 6
bytes (the difference between the 8 bytes required for a long address and the 2 bytes required
for a short address).
7. if you are using encryption, the maximum achievable payload is reduced by 5 bytes.
Operation Maximum payload
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 41
Maximum payload summary tables
The following table indicates the maximum payload when using transmit compatibility with the Legacy
802.15.4 module (S1 hardware).
Encryption
Enabled Disabled
95 B 100 B
The following table indicates the maximum payload when using the application header and not using
encryption.Increment the maximum payload in 2 bytes if you are not using the application header.
Destination Address
Source Address Short Long
Short 114 B 108 B
Long 108 B 102 B
The following table indicates the maximum payload when using the application header andusing
encryption.Increment the maximum payload in 4 bytes if you are not using the application header.
Destination Address
Source Address Short Long
Short 101 B 95 B
Long 101 B 95 B
Work with Legacy devices
The Legacy 802.15.4 module (S1 hardware) transmits packets one by one. It does not transmit a
packet until it receives all expected acknowledgments of the previous packet or the timeout expires.
The new XBee/XBee-PRO S2C 802.15.4 RF Modules enhance transmission by implementing a
transmission queue that allows the device to transmit to several devices at the same time. Broadcast
transmissions are performed in parallel with the unicast transmissions.
This enhancement in the XBee/XBee-PRO S2C 802.15.4 RF Module can produce problematic
behaviorunder certain conditions if the receiver is a Legacy 802.15.4 module (S1 hardware).
The conditions are:
nThe sender is a XBee/XBee-PRO S2C 802.15.4 RF Module, and the receiver is a Legacy 802.15.4
module.
nThe sender has the Digi Header enabled (MM = 0 or 3) and RR (XBee Retries) > 0.
nThe sender sends broadcast and unicast messages at the same time to the Legacy 802.15.4
module without waiting for the transmission status of the previous packet.
The effect is:
Operation Networking
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 42
nThe receiver may display duplicate packets.
The solution is:
nSet bit 0 of the C8 (802.15.4 Compatibility) parameter to 1 to enable TX compatibility mode in the
XBee/XBee-PRO S2C 802.15.4 RF Module. This eliminates the transmission queue to avoid sending
to multiple addresses simultaneously. It also limits the packet size to the levels of the Legacy
802.15.4 module.
Networking
The following table describes some common terms we use when discussing networks.
Term Definition
Association Establishing membership between end devices and a coordinator.
Coordinator A full-function device (FFD) that provides network synchronization by polling nodes.
End device When in the same network as a coordinator. Devices that rely on a coordinator for
synchronization and can be put into states of sleep for low-power applications.
PAN Personal Area Network. A data communication network that includes one or more
end devices and optionally a coordinator.
MAC Mode configuration
Medium Access Control (MAC) Mode configures two functions:
1. Enables or disables the use of a Digi header in the 802.15.4 RF packet.
When the Digi header is enabled (MM = 0 or 3), duplicate packet detection is enabled as well as
certain AT commands.
Modes 1 and 2 do not include a Digi header, which disables many features of the device. All data
is strictly pass through.
2. Enables or disables MAC acknowledgment request for unicast packets.
When MACACK is enabled (MM = 0 or 2), transmitting devices send packets with an ACK
request soreceiving devices send an ACK back (acknowledgment of RF packet reception)to
the transmitter. If the transmitting device does not receive the ACK, it re-sends the packet
upto three times or until the ACK is received.
Modes 1 and 3 disable MAC acknowledgment. Transmitting devices send packets without an
ACK request soreceiving devices do not send an ACK back to the transmitter.
Broadcast messages are always sent with the MACACK request disabled.
The followingtable summarizesthe functionality.
Mode Digi Header MAC ACK
0 (default) V V
1
2 V
3 V
Operation Networking
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 43
The default value for the MM configuration parameter is 0 which enables both the Digi header and the
MAC acknowledgment.
XBee retries configuration
Configures the maximum number ofretries the device executes in addition to the threeretries
provided by the 802.15.4 MAC. RR (XBee Retries) controls XBee retries configuration. It is also known
as Application Retries.
For each XBeeretry, the 802.15.4 MAC can execute up to three retries.
This only applies if MAC Mode configuration has Digi Header enabled.
Transmit status based on MAC mode and XBee retries configurations
When working in API mode, a transmit request frame sent by the user is always answered with a
transmit status frame sent by the device, if the frame ID is non-zero.
The following tables report the expected transmit status for unicast transmissions and the maximum
number of MAC and application retries the device attempts.
The tables also report the transmit status reported when thedevice detects energy above the CCA
threshold(when a CCA failure happens).
The following table applies in either of these cases:
lDigi Header is disabled.
lDigi Header is enabled and XBee Retries (RR parameter) is equal to 0 (default configuration).
Mac ACK
Config
Destination reachable Destination unreachable
CCA failure
happened
TX status
Retries
TX status
Retries TX
status
Retries
MAC App MAC App MAC App
Enabled 00
(Success)
up to
3
0 01 (No
acknowledgment
received)
3 0 02 (CCA
failure)
3 0
Disabled 00
(Success)
0 0 00 (Success) 0 0 02 (CCA
failure)
3 0
The following table applies when:
lDigi Header is enabled and XBee Retries (RR parameter) is bigger than 0.
/’\
Operation Networking
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide 44
Mac ACK
Config
Destination reachable Destination unreachable
CCA failure
happened
TX status
Retries
TX status
Retries TX
status
Retries
MAC App MAC App MAC App
Enabled 00
(Success)
up to 3
per app
retry
up to
RR
value
21
(Network
ACK Failure)
3RR
value
02 (CCA
failure)
3RR
value
Disabled 00
(Success)
0 up to
RR
value
21
(Network
ACK Failure)
0RR
value
02 (CCA
failure)
3RR
value
Peer-to-peer networks
By default, XBee/XBee-PRO S2C 802.15.4 RF Module modules are configured to operate within a peer-
to-peer network topology and therefore are not dependent upon master/slave relationships. This
means that devices remain synchronized without the use of master/server configurations and each
device in the network shares both roles of master and slave. Our peer-to-peer architecture features
fast synchronization times and fast cold start times. This default configuration accommodates a wide
range of RF data applications.
Master/slave networks
In a Master Slave network, there is a coordinator and one or more e