Digi XTend vB User Manual
XTend vB
Radio Frequency (RF) Module
User Guide
Revision history—90001478
Revision Date Description
A December
2015
B May 2016
C May 2018 Added note on range estimation. Changed ICto ISED.
D June 2019 Added FCC publication 996369 related information. Changes for 2x06
Baseline release of the document.
Added information on the Australian variant. Updated cyclic sleep numbers.
Added the HS command.
firmware release.
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
XTend vB RF Module User Guide
2
Steps to reproduce
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Contact us at +1 952.912.3444 or visit us at www.digi.com/support.
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XTend vB RF Module User Guide
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Contents
XTend vB RF Module User Guide
Applicable firmware and hardware 10
XTend replacement numbers 10
Certification overview 10
Technical specifications
General specifications 12
Performance specifications 12
Networking specifications 13
Power requirements 13
Cyclic sleep current (mA, average) 14
Regulatory conformity summary 14
Hardware
Connect the hardware 16
Mechanical drawings 17
Pin signals 17
DC characteristics (Vcc=2.8-5.5 VDC) 20
Outputs 20
Inputs 20
Modes
Transparent and API operating modes 22
Transparent operating mode 22
API operating mode 22
Additional modes 22
Command mode 22
Binary Command mode 22
Idle mode 23
Receive mode 23
Sleep modes 23
Shutdown mode 23
Transmit mode 23
Enter Command mode 23
Send AT commands 24
Exit Command mode 24
XTend vB RF Module User Guide
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Enter Binary Command mode 25
Exit Binary Command mode 25
Binary Command mode FAQs 25
Sleep modes 26
Pin Sleep (SM = 1) 27
Serial Port Sleep (SM = 2) 27
Cyclic Sleep Mode (SM = 4 - 8) 28
Operation
Serial interface 31
UART data flow 31
Serial data 31
Flow control 31
Data In (DIN) buffer and flow control 32
Data Out (DO) buffer and flow control 33
Configure the XTend vB RF Module
Configure the device using XCTU 35
Program the XTend vB RF Module
Programming examples 36
Connect the device to a PC 36
Modify a device address 36
Restore device defaults 37
Send binary commands 37
Query binary commands 38
Commands
Command mode options 41
AT (Guard Time After) 41
BT (Guard Time Before) 42
CC (Command Sequence Character) 42
CF (Number Base) 42
CN (Exit Command Mode) 43
CT (Command Mode Timeout) 43
E0 (Echo Off) 44
E1 (Echo On) 44
Diagnostic commands 44
%V (Board Voltage) 44
DB (Received Signal Strength) 45
GD (Receive Good Count) 45
HV (Hardware Version) 46
RC (Ambient Power - Single Channel) 46
RE (Restore Defaults) 46
RM (Ambient Power) 47
RP (RSSI PWM Timer) 48
SH (Serial Number High) 48
SL (Serial Number Low) 49
TP (Board Temperature) 49
XTend vB RF Module User Guide
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TR (Transmit Error Count) 50
VL (Firmware Version - Verbose) 50
VR (Firmware Version - Short) 50
WA (Active Warning Numbers) 51
WN (Warning Data) 51
WS (Sticky Warning Numbers) 53
HS (Hardware Series) 53
MAC/PHY commands 53
AM (Auto-set MY) 53
DT (Destination Address) 54
HP (Preamble ID) 54
ID (Network ID) 55
MK (Address Mask) 55
MT (Multi-transmit) 55
MY (Source Address) 56
RN (Delay Slots) 56
RR (Retries) 57
TT (Streaming Limit) 57
RF interfacing commands 58
BR (RF Data Rate) 58
FS (Forced Synch Time) 58
MD (RF Mode) 59
PB (Polling Begin Address) 60
PD (Minimum Polling Delay) 60
PE (Polling End Address) 60
PK (Maximum RF Packet Size) 61
PL (TX Power Level) 61
TX (Transmit Only) 62
Security commands 62
KY (AES Encryption Key) 63
Serial interfacing commands 63
AP (API Enable) 63
BD (Interface Data Rate) 64
CD (GP02 Configuration) 65
CS (GP01 Configuration) 66
FL (Software Flow Control) 66
FT (Flow Control Threshold) 66
NB (Parity) 67
RB (Packetization Threshold) 67
RO (Packetization Timeout) 68
RT (GPI1 Configuration) 68
SB (Stop Bits) 69
Sleep commands 69
FH (Force Wakeup Initializer) 69
HT (Time before Wake-up Initializer) 70
LH (Wakeup Initializer Timer) 70
PW (Pin Wakeup) 71
SM (Sleep Mode) 71
ST (Time before Sleep) 72
Special commands 72
WR (Write) 73
API operation
API mode overview 75
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API frame specifications 75
Calculate and verify checksums 77
Escaped characters in API frames 77
Frame descriptions
Modem Status - 0x8A 80
Description 80
Modem status codes 81
Examples 81
16-bit Transmit Request- 0x01 83
Description 83
Format 83
Examples 84
Transmit Status - 0x89 85
Description 85
Delivery status codes 86
Examples 86
16-bit Receive Packet - 0x81 88
Description 88
Format 88
Examples 89
Regulatory information
FCC (United States) 91
OEM labeling requirements 91
FCC notices 91
RF exposure statement 92
XTend vB RF Module antenna options 93
FCC publication 996369 related information 98
ISED (Innovation, Science and Economic Development Canada) 100
Labeling requirements 100
Transmitters for detachable antennas 100
Detachable antennas 100
ACMA (Australia) 101
Power requirements 101
Network configurations
Network topologies 103
Point-to-point networks 103
Point-to-multipoint networks 103
Peer to peer networks 104
Addressing 105
Address recognition 106
Basic communications 106
Streaming mode (default) 106
Multi-transmit mode 107
Repeater mode 108
Polling mode (basic) 112
Acknowledged communications: Acknowledged mode 113
Acknowledged mode connection sequence 113
XTend vB RF Module User Guide
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Polling mode (acknowledged) 114
Development Kit
Development Kit contents 117
Interface hardware 117
XTIB-R RS-232/485 Interface Board 118
Configuration switch 118
I/O and Power LEDs 119
Serial port 119
RSSI LEDs 119
Power connector 119
XTIB-R DIP switch 119
Adapters 121
NULL Modem Adapter (male-to-male) 121
NULL Modem Adapter (female-to-female) 122
Serial Loopback Adapter 122
Male DB-9 to RJ-45 Adapter 123
Female DB-9 to RJ-45 Adapter 123
Interface protocols 123
RS-232 operation 124
RS-485 (2-wire) operation 126
RS-485 (4-wire) and RS-422 operation 128
XTend vB RF Module User Guide
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XTend vB RF Module User Guide
The XTend vB RF Module was engineered to provide customers with an easy-to-use radio frequency
(RF) solution that provides reliable delivery of critical data between remote devices. The module
transfers a standard asynchronous serial data stream, operates within the ISM 900 MHz frequency
band and offers two RF data rates of 10 kb/s and 125 kb/s for the United States and Canada variant.
It offers two RF data rates of 10 kb/s and 105 kb/s for the Australia variant.
Applicable firmware and hardware 10
XTend replacement numbers 10
Certification overview 10
XTend vB RF Module User Guide
9
XTend vB RF Module User Guide Applicable firmware and hardware
Applicable firmware and hardware
This manual supports the following firmware:
n 2xxx
It supports the following hardware:
n As the name suggests, the XTend vB RF Module is form factor and over the air compatible with
our XTend module.
XTend replacement numbers
The following table provides the part numbers you can use to replace XTend devices with the XTend
vB RF Module.
Legacy part number Replacement part number
XT09-MI XTP9B-DPM-001
XT09-SI XTP9B-DPS-001
XT09-MI-MESH XTP9B-DMM-001
XT09-SI-MESH XTP9B-DMS-001
Certification overview
The XTend vB RF Module contains an FCC/IC approved RF module. A separate variant of the XTend vB
RF Module contains an Australian approved RF module. For usage requirements, see Regulatory
information.
ISM (Industrial, Scientific and Medical) license-free 902-928 MHz frequency band.
Manufactured under ISO 9001:2000 registered standards.
XTend vB RF Module User Guide
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Technical specifications
The following tables provide the device's technical specifications.
WARNING! When operating at 1 W power output, observe a minimum separation distance
of 6 ft (2 m) between devices. Transmitting in close proximity of other devices can damage
the device's front end.
General specifications 12
Performance specifications 12
Networking specifications 13
Power requirements 13
Regulatory conformity summary 14
XTend vB RF Module User Guide
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Technical specifications General specifications
General specifications
The following table describes the general specifications for the devices.
Specification Value
Dimensions (RF/pin connectors not included) 3.70 x 6.10 x 0.48 cm (1.457 x 2.402 x 0.190 in)
Weight 16 g
RoHS Compliant
Manufacturing ISO 9001:2000 registered standards
Connector 20 pin 2 mm pitch header
Antenna connector options MMCX or RPSMA
Antenna impedance 50 Ω unbalanced
Operating temperature -40 °C to 85 °C
Maximum input RF level at antenna port 6 dBm
Digital outputs 2 output lines
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 Value
Frequency range
RF data rate (software selectable)
Transmit power (software selectable)
Channels 10 hopping sequences share 50 frequencies
Outdoor line of sight 10 kb/s Up to 40 miles
902 to 928 MHz US/Canada
915 to 928 MHz Australia
10 kb/s to 125 kb/s US/Canada
10 kb/s to 105 kb/s Australia
Up to 30 dBm (see Power requirements)
1
125 kb/s Up to 7 miles
1
Estimated based on a 9 mile range test with dipole antennas.
XTend vB RF Module User Guide
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Technical specifications Networking specifications
Specification Value
Indoor range line of sight 10 kb/s Up to 1,000 feet (300 m)
125 kb/s Up to 500 feet (150 m)
Receiver sensitivity 10 kb/s -110 dBm
125 kb/s -100 dBm
UARTdata rate 1200-230400 baud
Networking specifications
The following table provides the networking specifications for the device.
Specification Value
Modulation Frequency Shift Keying
Spread Spectrum Frequency Hopping Spread Spectrum (FHSS)
Supported Network
Topologies (software
selectable)
Encryption 256-bit or 128-bit AES CBC encryption depending on region. 256-bit is only
Power requirements
The following table describes the power requirements for the XTend vB RF Module.
Specifications are given at 5 V, 25 °C unless otherwise noted.
Requirement Value
Supply voltage 2.8 to 5.5 VDC, 5 V typical
Receive current @ 5 V 35 mA
Transmit current See the following table
Shutdown mode current 1 µA
Sleep current < 147 µA
Peer-to-peer (master/slave relationship not required), point-topoint/point-to-multipoint
available on the North America variant. 128-bit is only available on
international variants.
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Technical specifications Regulatory conformity summary
Cyclic sleep current (mA, average)
Sleep mode Cycle time RF data rate Cyclic sleep current (mA, average)
SM = 8 16 seconds BR = 0 0.65
BR = 1 0.23
SM = 7 8 seconds BR = 0 1.13
BR = 1 0.31
SM = 6 4 seconds BR = 0 2.06
BR = 1 0.46
SM = 5 2 seconds BR = 0 3.77
BR = 1 0.77
SM = 4 1 second BR = 0 6.68
BR = 1 1.36
Transmit power level 21.5 dBm 27 dBm 30 dBm
Supply voltage range 2.8 to 5.5 V 3.2 to 5.5 V 4.75 to 5.5 V
Transmit current (5 V, typical) 260 mA 470 mA 710 mA
Transmit current (3.3 V, typical) 340 mA 615 mA N/A
Regulatory conformity summary
This table describes the agency approvals for the devices.
Nation Approval
United States Contains FCC ID: MCQ-XBPSX
Canada Contains IC: 1846A-XBPSX
Australia RCM
XTend vB RF Module User Guide
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Hardware
Connect the hardware 16
Mechanical drawings 17
Pin signals 17
DC characteristics (Vcc=2.8-5.5 VDC) 20
XTend vB RF Module User Guide
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Hardware Connect the hardware
Connect the hardware
The following figure shows the XTend vB RF Module and accessories you need to get started and how
to connect them. The accessories are in the XT09-DK development kit.
Item Description
1 Antenna, RPSMA (female)
2 XTend vB module, RPSMA version shown
3 DIP switches
4 9 V power supply
5 DB9 serial cable
XTend vB RF Module User Guide
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Hardware Mechanical drawings
Mechanical drawings
The following drawings show the dimensions of the device.
Pin signals
The following drawing shows the location of the pins.
When integrating the module with a Host PC board, leave all lines that you do not use disconnected
(floating).
Pin
number Name I/O
High
impedance
during
shutdown
Must
connect Function
1 GND - - yes Ground
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Hardware Pin signals
High
impedance
Pin
number Name I/O
during
shutdown
Must
connect Function
2 VCC I - yes
3 GPO2/RXLED O - yes
4
5 DIN I yes yes Data In: Serial data entering the
6 DOUT O yes - Data Out: Serial data exiting the
7
TX _PWR
SHDN
O yes - Transmit_Power: Pin pulses low
I no yes Shutdown: Drive this pin high to
Power: 2.8 - 5.5 VDC
GPO2: General Purpose Output.
Default (CD = 2) drives this pin
low.
RX LED: Pin is driven high during
RF data reception; otherwise,
the pin is driven low. To enable
this pin, see CD (GP02
Configuration).
during RF transmission;
otherwise, the pin is driven high
to indicate power is on and the
device is not in Sleep or
Shutdown Mode.
device (from the UART host). For
more information, see .
module (to the UART host). For
more information, see .
enable normal operation and
low during Shutdown. Shutdown
enables the lowest power mode
available to the module.
8 SLEEP I yes -
XTend vB RF Module User Guide
SLEEP: By default, SLEEP is not
used. To configure this pin to
enable Sleep modes, refer to
Sleep modes, SM (Sleep Mode)
and PW (Pin Wakeup).
18
Hardware Pin signals
High
impedance
Pin
number Name I/O
during
shutdown
Must
connect Function
9
10
11
GPO1 / CTS /
RS-485 TX_EN
RTS / CMD
CONFIG/RSSI
O yes -
I yes -
1
I
O
no - Configuration: Pin can be used
2
no -
GPO1: General Purpose Output.
Pin can be driven low or high.
CTS (Clear-to-Send): CTS is
enabled by default. When the pin
is driven low, the UART host is
permitted to send serial data to
the device. For more
information, see and CS (GP01
Configuration).
RS-485 Transmit Enable:
Enables RS-485 half and fullduplex communications. For
more information, see and CS
(GP01 Configuration).
RTS (Request-to-Send):
Not used by default. This pin can
be configured to allow the UART
host to regulate the flow of
serial data exiting the module.
For more information, see and
RT (GPI1 Configuration).
as a backup method for
entering Command mode during
power-up.
Receive Signal Strength
Indicator: By default, pin is used
as an RSSI PWM output after at
the conclusion of the power-up
sequence. The line is also pulled
high when the device goes to
sleep. The PWM output is 2.8 Vlevel. For more information, see
RP (RSSI PWM Timer).
12 - 20 Reserved / do
not connect
1
The RF module has a 10 kΩ internal pull-up resistor.
2
The RF module has a 10 kΩ internal pull-up resistor.
XTend vB RF Module User Guide
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Hardware DC characteristics (Vcc=2.8-5.5 VDC)
DC characteristics (Vcc=2.8-5.5 VDC)
Outputs
Pin
number Pin name
3 GPO2/RXLED VCC – 0.7 V 0.55 V
4 TX _PWR VCC – 0.7 V 0.55 V
6 DOUT VCC – 0.7 V 0.55 V
9 GPO1 / CTS / RS-485 TX_ENVCC – 0.7 V 0.55 V
1,2
11
CONFIG / RSSI 2.2 V 0.5 V
VOHminimum (IOH= -6
mA)
VOLmaximum (IOL = 6
mA)
Inputs
Pin number Pin name
5 DIN VCC * 0.75 VCC * 0.25
7 SHDN VCC * 0.75 0.7 V
8 SLEEP VCC * 0.75 VCC * 0.25
10 RTS / CMD VCC * 0.75 VCC * 0.25
3,4
11
CONFIG / RSSI VCC * 0.75 VCC * 0.25
VIHminimum VILmaximum
1
The RF Module has an internal 10 kΩ pull-up resistor to VCC.
2
When the line is enabled for use as RSSI PWM output and not CONFIG input. RSSI signal is a 2.8 V level PWM
signal.
3
The RF Module has an internal 10 kΩ pull-up resistor to VCC.
4
When the line is enabled for use as CONFIG input and not RSSI PWM output.
XTend vB RF Module User Guide
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Modes
The XTend vB RF Module is in Receive Mode when it is not transmitting data. The device shifts into the
other modes of operation under the following conditions:
n Transmit mode (Serial data in the serial receive buffer is ready to be packetized)
n Sleep mode
n Command Mode (Command mode sequence is issued)
Transparent and API operating modes 22
Additional modes 22
Sleep modes 26
XTend vB RF Module User Guide
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Modes Transparent and API operating modes
Transparent and API operating 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.
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.
API operating mode
API operating mode is an alternative to Transparent operating mode. API mode is a frame-based
protocol that allows you to direct data on a packet basis. The device communicates UART data in
packets, also known as API frames. This mode allows for structured communications with computers
and microcontrollers.
The advantages of APIoperating mode include:
n It is easier to send information to multiple destinations
n The host receives the source address for each received data frame
n You can change parameters without entering Command mode
n You can query or set a configuration parameter while a pending command—for example ND—is
in progress. This cannot be done in Command mode.
For more information, see API frame specifications.
Additional modes
In addition to the serial communication modes, several modes apply to how to configure devices and
how devices communicate with each other.
Command mode
Command mode is a state in which the firmware interprets incoming characters as commands.
Command mode allows you to modify the device’s firmware using parameters you can set using AT
commands. When you want to read or set any setting of the device, you have to send it an AT
command. Every AT command starts with the letters "AT" followed by the two characters that identify
the command the device sends and then by some optional configuration values. For more details, see
Enter Command mode.
Binary Command mode
Binary Command mode allows you to configure a device at a faster rate than AT commands will allow.
Using binary commands to send and receive parameter values is the fastest way to change the
operating parameters of the device. Use binary commands to:
n Sample signal strength and/or error counts;
n Change device addresses and channels for polling systems when a quick response is necessary.
For more details, see Enter Binary Command mode and DB (Received Signal Strength).
XTend vB RF Module User Guide
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Modes Additional modes
Idle mode
When not receiving or transmitting data, the device is in Idle mode. During Idle mode, the device
listens for valid data on the serial port.
Receive mode
If a destination node receives a valid RF packet, the destination node transfers the data to its serial
transmit buffer. For the serial interface to report receive data on the RF network, that data must
meet the following criteria:
n ID match
n Channel match
n Address match
Sleep modes
Sleep Modes enable the device to enter states of low-power consumption when not in use. The device
supports three software sleep modes:
n Pin Sleep: the host controls this
n Serial Port Sleep: wakes when it detects serial port activity
n Cyclic Sleep: wakes when it detects RF activity
For more information, see Sleep modes.
Shutdown mode
Shutdown mode offers the lowest power mode available to the device. This is helpful for applications
that must keep power consumption to a minimum during idle periods.
When you drive the SHDN pin (pin 7) low, it forces the device into Shutdown mode. This halts any
communication in progress (transmit or receive) and any buffered data is lost. For any other mode of
operation, you must drive or pull SHDN high.
Immediately after the SHDN pin changes states from low to high, the device resets. After reset, the
application must observe a delay time of <100 ms.
While SHDN is driven low, the device sets the following pins to high impedance: DCD, TX_PWR, RX LED,
DO and CTS. The SHDN line is driven low during shutdown.
The following input pins may continue to be driven by external circuitry when in shutdown mode: RTS,
DI and SHDN.
Because the DO pin is set to high impedance during Shutdown, if the XTend vB RF Module is connected
to a processor, the UART receive pin could be floating. Place a weak pull-up between the device and
the microcontroller so that the application does not misinterpret noise as data.
Transmit mode
When the device receives serial data and is ready to packetize it, the device exits Idle mode and
attempts to transmit the serial data.
Enter Command mode
There are two ways to enter Command mode:
XTend vB RF Module User Guide
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Modes Additional modes
1. To get a device to switch into this mode, you must issue a unique string of text in a special way:
+++ (default). When the device sees a full second of silence in the data stream followed by the
string +++ (without Enter or Return) and another full second of silence, it knows to stop
sending data through and start accepting commands locally.
Do not press Return or Enter after typing +++ because it will interrupt the guard time silence
and prevent you from entering Command mode.
2. If a serial break (DIN held low) signal is sent for over five seconds, the device resets, and it
boots into Command mode with default baud settings (9600 baud).
3. If a serial break is observed upon boot, Command mode will similarly be entered.
The device sends the letters OK followed by a carriage return out of the UART to indicate that it
entered Command mode.
You can customize the guard times and timeout in the device’s configuration settings. See CC
(Command Sequence Character), BT (Guard Time Before) and AT (Guard Time After).
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 letters AT, which stands for "attention." The AT is 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 enables software flow control.
Multiple AT commands
You can send multiple AT commands at a time when they are separated by a comma in Command
mode; for example, ATSH,SL.
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 FFFF or 0xFFFF.
Response to AT commands
When reading parameters, the device returns the current parameter value instead of an OK message.
Exit Command mode
1. Send followed by a carriage return.
or:
2. If the device does not receive any valid AT commands within the time specified by, it returns to
Transparent or API mode. The default Command mode timeout is10seconds.
For an example of programming the device using AT Commands and descriptions of each configurable
parameter, see AT commands.
XTend vB RF Module User Guide
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Modes Additional modes
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 is10seconds.
For an example of programming the device using AT Commands and descriptions of each configurable
parameter, see Commands.
Enter Binary Command mode
To enter Binary Command mode, you must first be in Command mode:
1. Set RT to 1; see RT (GPI1 Configuration).
2. Assert CMD by driving pin 10 high to enter Binary Command mode.
3. Disable hardware flow control.
CTS (pin ) is high when the firmware executes a command. That is why you must disable hardware
flow control, because CTS holds off parameter bytes.
Exit Binary Command mode
To exit Binary Command mode, de-assert CMD by driving pin 10 low.
Binary Command mode FAQs
Since sending and receiving binary commands takes place through the same serial data path as live
data, interference between the two types of data can be a concern. Some common questions about
using binary commands are:
n What are the implications of asserting CMD while the device is sending or receiving live data?
You must assert the CMD pin (pin 10) in order to send binary commands to the device. You can
assert the CMD pin to recognize binary commands anytime during the transmission or reception of
data.
The device only checks the status of the CMD signal at the end of the stop bit as the byte shifts
into the serial port.
The firmware does not allow control over when the device receives data, except by waiting for
dead time between bursts of communication.
If the command is sent in the middle of a stream of payload data, the device executes the
command in the order it is received. If the device is continuously receiving data, it waits for a break
in the data it receives before executing the command.
n After sending serial data, is there a minimum time delay before you can assert CMD?
n Is a time delay required after CMD is de-asserted before payload data can be sent?
The host must observe a minimum time delay of 100 µs after sending the stop bit of the command
byte before the host de-asserts the CMD pin. The command executes after the host sends all of its
associated parameters. If the device does not receive all of these parameters within 0.5 seconds,
the device returns to Idle mode.
XTend vB RF Module User Guide
25
Modes Sleep modes
Note When a host sends parameters, they are two bytes long with the least significant byte sent first.
Binary commands that return one parameter byte must be written with two parameter bytes.
Example: to set PL to 3, send the following data: 0x3A 0x03 0x00 (Binary Command, LSB, MSB).
n How do I discern between live data and data received in response to a command?
To query command parameters using Binary Command mode, set the most significant bit of the
binary command. This can be accomplished by logically ORing (bit-wise) the binary command with
hexadecimal 0x80. The parameter bytes are returned in hexadecimal bytes with the least
significant bit first (if multiple bytes are returned).
Example: to query HP in Binary Command mode, instead of setting it, send 0x11 (HP binary
command) as 0x91 with no parameter bytes.
The device must be in Binary Command mode in order for the device to recognize a binary
command; see Enter Binary Command mode.
If the device is not in Binary Command mode (the RT parameter value is not 1), the device does not
recognize that the CMD pin is asserted and therefore does not recognize the data as binary
commands.
For an example of binary programming, see Send binary commands.
Sleep modes
For the device to enter one of the sleep modes, SM must have a non-zero parameter value, and it
must meet one of the following conditions:
1. The device is idle (no data transmission or reception) for the amount of time defined by the ST
parameter. ST is only active when SM = 2 or 4 - 8.
2. The host asserts SLEEP (pin 10). This only applies to the Pin Sleep option.
When in Sleep mode, the device does not transmit or receive data until it transitions to Idle mode.
Use the SM command to enable or disable all Sleep modes. The following table shows the transitions
into and out of Sleep modes.
Sleep
mode
(setting)
Pin Sleep
(SM = 1)
Transition into
Sleep mode
Assert (high) SLEEP pin. A
microcontroller can shut down
and wake devices via the
SLEEP pin.
The device completes a
transmission or reception
before activating Pin Sleep.
Transition out of Sleep
mode (wake)
De-assert (low) SLEEP pin SM < 147 µA
Related
commands
Power
consumption
XTend vB RF Module User Guide
26
Modes Sleep modes
Sleep
mode
(setting)
Transition into
Sleep mode
Transition out of Sleep
mode (wake)
Related
commands
Power
consumption
Serial
Port
Sleep
(SM = 2)
Cyclic
Sleep
(SM = 4 -
8)
The SM (Sleep Mode) command is central to setting all Sleep Mode configurations. By default, Sleep
Modes are disabled (SM = 0) and the device remains in Idle/Receive Mode. When in this state, the
device remains constantly ready to respond to serial or RF activity.
Note When the device sleeps, the RSSI pin is pulled high by design.
Automatic transition to Sleep
Mode occurs after a userdefined period of inactivity (no
transmitting or receiving of
data).
Period of inactivity is defined
by the ST command.
The device transitions in and out of Sleep Mode in cycles
(you set the sleep interval of time using the SM command).
The cyclic sleep interval of time must be shorter than the
interval of time that is defined by the LH command.
You can force the device into Idle Mode using the SLEEP pin
if you send the PW command.
When a serial byte is
received on the DI pin
(SM), ST 7.3 mA
(SM), ST,
HT, LH, PW
See Power
requirements
Pin Sleep (SM = 1)
After enabling Pin Sleep, the SLEEP pin controls whether the device is active or sleeping. When the
host de-asserts SLEEP, the device is fully operational. When the host asserts SLEEP, the device
transitions to Sleep mode and remains in its lowest power-consuming state until the host de-asserts
the pin. This pin is only active if the device is setup to operate in this mode; otherwise the firmware
ignores the pin.
Once in Pin Sleep, the device de-asserts (high) CTS (pin 9) , indicating that other devices should not
send data to the device. The device also de-asserts (low) the TX_PWR line (pin 4) when the device is in
Pin Sleep mode.
You cannot assert the SLEEP (pin9) until the transmission of the second byte has started.
Note The device completes a transmission or reception before activating Pin Sleep.
Serial Port Sleep (SM = 2)
n Wake on serial port activity
Serial Port Sleep is a Sleep mode in which the device runs in a low power state until it detects serial
data on the DI pin.
The ST command determines the period of time that the device sleeps. Once it receives a character
through the DI pin, the device returns to Idle mode and is fully operational.
XTend vB RF Module User Guide
27
Modes Sleep modes
Cyclic Sleep Mode (SM = 4 - 8)
Cyclic Sleep modes allow device wakes according to the times designated by the cyclic sleep settings.
If the device detects a wake-up initializer during the time it is awake, the device synchronizes with the
transmitting device and receives data after the wake-up initializer runs its duration. Otherwise, the
device returns to Sleep mode and continues to cycle in and out of activity until a wake-up initializer is
detected.
While the device is in Cyclic Sleep mode, it de-asserts (high) CTS (pin 9) to indicate not to send data to
the device. When the device awakens to listen for data, it asserts CTS and transmits any data received
on the DI pin. The device also de-asserts (low) the TX_PWR (pin 4) when it is in Cyclic Sleep mode.
The device remains in Sleep mode for a user-defined period of time ranging from 1 second to 16
seconds (SM parameters 4 through 8). After this interval of time, the device returns to Idle mode and
listens for a valid data packet. The listen time depends on the BR parameter setting. The default BR
setting of 1 requires at least a 35 ms wake time, while the BR setting of 0 requires a wake time of up
to 225 ms. If the device does not detect valid data on any frequency, it returns to Sleep mode. If it
detects valid data, it transitions into Receive mode and receives the incoming RF packets. The device
then returns to Sleep mode after a period of inactivity determined by the ST parameter.
You can also configure the device to wake from cyclic sleep when the SLEEP pin is de-asserted. To
configure a device to operate in this manner, you must send the PW (Pin Wake-up) command. When
you de-assert the SLEEP pin, it forces the device into Idle mode and it can begin transmitting or
receiving data. It remains active until it no longer detects data for the time that ST specifies, at which
point it resumes its low-power cyclic state.
Cyclic scanning
Each RF transmission consists of an RF initializer and payload. The RF initializer contains initialization
information and all receiving devices must wake during the wake-up initializer portion of data
transmission in order to synchronize with the transmitting device and receive the data.
The cyclic interval time defined by the SM (Sleep Mode) command must be shorter than the interval
time defined by LH (Wake-up Initializer Timer) command.
Correct configuration (LH > SM)
In the following figure, the length of the wake-up initializer exceeds the time interval of Cyclic Sleep.
The receiver is guaranteed to detect the wake-up initializer and receive the accompanying payload
data.
The LH (Wakeup Initializer Timer) is only enabled if the HT (Time before Wake-up Initializer) is nondefault. The Wakeup Initializer is resent at the beginning of every packet unless the HT is set. Set HT
less than or equal to the ST (Time before Sleep) such that once the XTend vB RF Module has received
the Wakeup Initializer, another Wakeup Initializer need not be sent again until the expiration of the ST
has expired.
XTend vB RF Module User Guide
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Modes Sleep modes
Incorrect configuration (LH < SM)
Length of wake-up initializer is shorter than the time interval of Cyclic Sleep. This configuration is
vulnerable to the receiver waking and missing the wake-up initializer (and therefore also the
accompanying payload data).
XTend vB RF Module User Guide
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Operation
WARNING! When operating at 1 W power output, observe a minimum separation distance
of 6 ft (2 m) between devices. Transmitting in close proximity of other devices can damage
the device's front end.
Serial interface 31
UART data flow 31
Serial data 31
Flow control 31
XTend vB RF Module User Guide
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