Digi, Digi International, the Digi logo, and XTend are trademarks or registered
trademarks of Digi International, Inc. in the United States and other countries
worldwide. All other trademarks are the property of their respective owners.
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, either
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.
- Distributions of AES source code include the above copyright notice, this list of
conditions and disclaimer.
- Distributions in binary form include the above copyright notice, this list of conditions and disclaimer in the documentation and/or other associated materials.
- The copyright holder's name is not used to endorse products built using this
software without specific written permission.
Alternatively, provided that this notice is retained in full, this product may be distributed under the terms of the GNU General Public License (GPL), in which case
the provisions of the GPL apply INSTEAD OF those given above.
Disclaimer - This AES software is provided 'as is' with no explicit or implied warranties in respect of its properties, including, but not limited to, correctness and/or
fitness for purpose.
The 9XTend RF Modem affords OEMs and integrators an easy-to-use RF
solution that sustains reliable delivery of data between remote devices.
Out-of-box, the modem is configured to immediately sustain long range
wireless links between devices. Simply feed serial data into one modem,
then the data will surface on the other end of the wireless link. The modem
transfers a standard asynchronous serial data stream between devices.
1.1. Key Features
Long Range Data Integrity
1 Watt Power Output (variable 1mW - 1W)
Range (@9,600 bps throughput data rate):
• Indoor/Urban: up to 3000’ (900 m)
• Outdoor RF line-of-sight:
up to 14 miles (22 km) w/dipole antenna
• Outdoor RF line-of-sight:
up to 40 miles (64 km) w/high-gain antenna
Range (@115,200 bps throughput data rate):
• Indoor/Urban: up to 1500’ (450 m)
• Outdoor RF line-of-sight:
up to 7 miles (11 km) w/dipole antenna
• Outdoor RF line-of-sight:
up to 20 miles (32 km) w/high-gain antenna
Continuous RF data stream up to 115,200 bps
Receiver Sensitivity: -110 dBm (@ 9600 baud),
–100 dBm (@ 115200 baud)
Advanced Networking & Security
True Peer-to-Peer (no Master device required),
Point-to-Point, Point-to-Multipoint & Multidrop
Retries and Acknowledgements
FHSS (Frequency Hopping Spread Spectrum)
10 hopping channels, each with over 65,000
unique network addresses available
256-bit AES Encryption
(AES algorithm is FIPS-197 certified)
Low Power
7 - 28 V Supply Voltage
Pin, Serial Port and Cyclic
software sleep modes supported
Easy-to-Use
No configuration necessary for out-of box
RF communications
(parity, start and stop bits, etc.)
XII™ Interference Immunity
Free & Unlimited Technical Support
, RTS, DCD, DTR (& more)
1.1.1. Worldwide Acceptance
FCC Approved (USA) Refer to “Appendix A: Agency Certifications” on page 60 for
FCC Requirements.
Systems that include XTend RF Modems inherit Digi’s Certifications.
ISM (Industrial, Scientific & Medical) license-free 902-928 MHz frequency band
Manufactured under ISO 9001:2000 registered standards
ESD (Electrostatic Discharge) immunity - ESD-hardened and IEC1000-4-2 (Level 4) tested
4
9XTend™ RS-232/422/485 RF Modem User’s Guide
9XTend RF Modems are optimized for use in the US, Canada, Australia and Israel
1.2. Specifications
Out-of-box, the 9XTend RF Modem is configured to provide immediate long range wireless links
between devices. The modem can be configured to support additional functional ity through the
use of standard AT and binary commands. Refer to p21 and p23 for more information..
Performance@9600 bps Throughput Data Rate@115200 bps Throughput Data Rate
Transmit Power Output
(software selectable using PL command)
Indoor/Urban RangeUp to 3000’ (900 m)Up to 1500’ (450 m)
Outdoor
RF line-of-sight Range
Interface Data Rate
(software selectable using BD command)
Throughput Data Rate
(software selectable using BR command)
RF Data Rate10,000 bps125,000 bps
Receiver Sensitivity-110 dBm-100 dBm
Power Requirements
Supply Voltage7 - 28V7 - 28V
Receive Current110 mA110 mA
Pin Sleep Power-down17 mA17 mA
Serial Port Sleep Power Down45 mA45 mA
16 sec cyclic sleep (SM=8)20 mA19 mA
8 sec cyclic sleep (SM=7)21 mA19 mA
Idle Currents
Networking & Security
Frequency902-928 MHz
Spread SpectrumFHSS (Frequency Hopping Spread Spectrum)
ModulationFSK (Frequency Shift Keying)
Network Topologies SupportedPeer-to-Peer (“Master/Slave” relationship not required), Point-to-Point, Point-to-Multipoint & Multidrop
Channel Capacity10 hop sequences share 50 frequencies
Encryption256-bit AES Encryption – To implement, refer to the “KY (AES Encryption Key) Command” on page 35
Physical Properties
RF Modem Board Size2.750” x 5.500” x 1.125” (6.99cm x 13.97” x 2.86cm)
Weight7.1 oz. (200g)
Serial ConnectorDB-9
Operating Temperature-40 to 85º C (industrial)
Antenna
ConnectorRPSMA (Reverse-polarity SMA)
Impedance50 ohms unbalanced
Certifications (partial list)
FCC Part 15.247OUR-9XTEND
Industry Canada (IC)4214A-9XTEND
4 sec cyclic sleep (SM=6)24 mA20 mA
2 sec cyclic sleep (SM=5)30 mA22 mA
1 sec cyclic sleep (SM=4)39 mA25 mA
1mW - 1 Watt1mW - 1 Watt
Up to 14 miles (22 km) w/ dipole antenna
Up to 40 miles (64 km) w/ high-gain antenna
1200 – 230400 bps1200 – 230400 bps
9,600 bps115,200 bps
Up to 7 miles (1 1 km ) w/ dipole antenna
Up to 20 miles (32 km) w/ high-gain antenna
Table 1-02. 9XTend-PKG-R RS-232/422/485 RF Modem Specifications - Relative to user-selected TX Power Output
Power Requirements (TX currents relative to each TX Power Output option)
Transmit Power Output1 mW10 mW100 mW500 mW1 W
Typical Transmit Current @9.6 Kbps
(9 VDC supply voltage)
110 mA145 mA250 mA510 mA900 mA
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Table 1-02. 9XTend-PKG-R RS-232/422/485 RF Modem Specifications - Relative to user-selected TX Power Output
Power Requirements (TX currents relative to each TX Power Output option)
Typical Transmit Current @11 5.2 Kbps)
(9 VDC supply voltage)
110 mA140 mA245 mA500 mA800 mA
6
9XTend™ RS-232/422/485 RF Modem User’s Guide
1.3. External Interface
1-01a. Config (Configuration) Switch
Figure 1-01. Front View
1-01c.
DB-9 Seria l P ort
1-01d
RSSI LEDs
1-01b.
I/O & Power LEDs
1-01a.
Config Switch
* Note: The XTend RF modem can accept
voltages as low as 5V.
Contact Digi Technical Support
to implement this option.
1-01e.
Power Connector
The Config Switch provides an alternate method for entering into
Command Mode. T o enter Command Mode at the default RF data rate
of the modem, hold the Config Switch down for two seconds.
1-01b. I/O & Power LEDs
LEDs indicate modem activity as follows:
Yellow (top LED)= Serial Data Out (to host)
Green (middle) = Serial Data In (from host)
Red (bottom) = Power/TX Indicator (Red light is on when
powered; it pulses on/off briefly during RF transmission.)
1-01c. DB-9 Serial Port
Standard female DB-9 (RS-232) connector. This connector can be
also used for RS-485 and RS-422 connections.
1-01d. RSSI LEDs
RSSI LEDs indicate the amount of fade margin present in an active
wireless link. Fade margin is defined as the difference between the
incoming signal strength and the modem's receiver sens itivity.
3 LEDs ON= Very Strong Signal (> 30 dB fade margin)
2 LEDs ON= Strong Signal (> 20 dB fade margin)
1 LED ON= Moderate Signal (> 10 dB fade margin)
0 LED ON= Weak Signal (< 10 dB fade margin)
1-01e. Power Connector
7-28 VDC* power connector (Center positive, 5.5/2.1mm)
1-02a. DIP Switch
Figure 1-02. Back ViewDuring each power-on sequence (reset or boot), the modem is auto-
matically configured according to the positions of the DIP Switch. The
DIP Switch provides integrators with a limited number of external
programming options. [Refer to Figure 1-03 for confi gur ati on options]
1-02b. Antenna Port
The antenna port is a 50Ω RF signal connector for connecting to an
external antenna. The connector type is RPSMA (Reverse Polarity
1-02a.
DIP Switch
Figure 1-03. DIP Switch Settings of the XTIB-R (RS-232/485) Interface Board
1-02b.
Antenna Conector
SMA) female. The connector has threads on the outside of a barrel
and a male center conductor.
Refer to the tables in “Automatic
DIP Switch Configurations” on
page 23 regarding configurations
triggered by the positions of the
DIP Switch (during power-up).
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9XTend™ RS-232/422/485 RF Modem User’s Guide
2. Interfacing Protocol
The 9XTend RS-232/422/485 RF Modem supports the following interfacing protocols:
• RS-232
• RS-485 (2-wire) Half-duplex
• RS-485 (4-wire) and RS-422
2.1. RS-232 Operation
2.1.1. DIP Switch Settings and Pin Signals
Figure 2-01.
RS-232 DIP Switch Settings
DIP Switch settings are read and applied
only while powering-on.
Table 2-01. RS-232 Signals and their implementations on the XTend RF Modem
DB-9 Pin
(Low-asserted signals are distinguished by horizontal line over pin name.)
RS-232
Name
1DCDGPO2Data-Carrier-DetectConnected to DSR (pin6)
2RXDDOReceived DataSerial data exiting the RF modem (to host)
3TXDDITransmitted DataSerial data entering into the RF modem (from host)
4DTRGPI2Data-Terminal-ReadyCan enable Power-Down on the RF modemy
Pin Reference
Name*
Figure 2-02.
Pins used on the female RS-232 (DB-9)
DescriptionImplementation
5GND-Ground SignalGround
6DSRGPO2Data-Set-ReadyConnected to DCD (pin1)
7
8CTSGPO1Clear-to-SendProvides CTS flow control
9RI-Ring Indicator
* The ‘Pin Reference Name’ provides an associative tag that references commands used to define pin behaviors.
GPI stands for "General Purpose Input" and GPO stands for "General Purpose Output". As an example, the CD
command is used to define the behavior of GPO2 (DB-9 pin number 1). The ‘Pin Reference Name’ is the name
used when referring to XTend commands and parameters.
RTS
CMD
/
GPI1
Request-to-Send /
Command Mode
Provides RTS
Optional power input that is connected internally to the
flow control or enables Command Mode
positive lead of the front power connector
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9XTend™ RS-232/422/485 RF Modem User’s Guide
2.1.2. Wiring Diagrams
Figure 2-03. RS-232 DTE Device (male DB-9 connector) wired to a DCE RF modem (female DB-9)
Figure 2-04. DCE RF modem (female DB-9 connector) wired to an RS-232 DCE Device (male DB-9)
Termination is the 120 Ω resistor between T+ and T-.
DIP Switch settings are read and applied
only while powering-on.
Note: Refer to Figure 2-15 and Figure 2-16 for the RJ-45 connector pin designations used in
RS-485/422 environments.
Table 2-02. RS-485 (2-wire half-duplex) signals and their implementations on the XTend RF Modem
DB-9 PinRS-485 NameDescriptionImplementation
2T/R- (TRA)Negative Data LineTransmit serial data to and from the RF modem
5GNDGround SignalGround
8T/R+ (TRB)Positive Data LineTransmit serial data to and from the RF modem
9PWRPower
1, 3, 4, 6, 7not used
Figure 2-07.
Pins used on the female RS-232 (DB-9)
Serial Connector
Optional power input that is connected internally
to the front power connector
2.2.2. Wiring Diagram
Figure 2-09. XTend RF Modem in an RS-485 (2-wire) half-duplex environment
Termination is the 120 Ω resistor between T+ and T-.
DIP Switch settings are read and applied
only while powering-on.
Table 2-03. RS-485/422 (4-wire) Signals and their implementations on the XTend RF Modem
DB-9 Pin
2T- (TA)
3R- (RA)
5GNDSignal GroundGround
7R+ (RB)
8T+ (TB)
9PWRPower
1, 4, 6not used
RS-485/422
Name
DescriptionImplementation
Transmit Negative
Data Line
Receive Negative
Data Line
Receive Positive
Data Line
Transmit Positive
Data Line
Figure 2-11.
Pins used on the female RS-232 (DB-9)
Serial Connector
Serial data sent from the RF modem
Serial data received by the RF modem
Serial data received by the RF modem
Serial data sent from the RF modem
Optional power input that is connected internally
to the front power connector
2.3.2. Wiring Diagrams
Figure 2-13. XTend RF Modem in an RS-485 (4-wire) environment
11
9XTend™ RS-232/422/485 RF Modem User’s Guide
Figure 2-14. XTend RF Modem in an RS-422 environment
RS-485/422 Connection Guidelines
The RS-485/422 protocol provides a solution for wired communications that can tolerate high
noise and push signals over long cable lengths. RS-485/422 signals can communicate as far as
4000 feet (1200 m). RS-232 signals are suitable for cable distances up to 100 feet (30.5 m).
RS-485 offers multi-drop capability in which up to 32 nodes can be connected. The RS-422 protocol is used for point-to-point communications.
Suggestions for integrating the XTend RF Modem with the RS-485/422 protocol:
1.When using Ethernet twisted pair cabling: Select wires so that T+ and T- are connected to
each wire in a twisted pair. Likewise, select wires so that R+ and R- are connected to a
twisted pair. (For example, tie the green and white/green wires to T+ and T-.)
2.For straight-through Ethernet cable (not cross-over cable) - The following wiring pattern
works well: Pin3 to T+, Pin4 to R+, Pin5 to R-, Pin6 to T-
3.Note that the connecting cable only requires 4 wires (even though there are 8 wires).
4.When using phone cabling (RJ-11) - Pin2 in the cable maps to Pin3 on opposite end of
cable and Pin1 maps to Pin4 respectively.
Figure 2-15. Male DB-9 to RJ-45 Adapter (yellow)
Figure 2-16. Female DB-9 to RJ-45 Adapter (green)
An XTend RS-232/422/485 RF Modem ‘Accessories Kit’ is available that includes connectors that
facilitate RS-485/422 and other serial communications. Refer to “Appendix B: Development Guide” on
page 65 for information regarding the connectors and tools included in the kit.
12
9XTend™ RS-232/422/485 RF Modem User’s Guide
3. RF Modem Operation
WARNING: When operating at 1 Watt power output, observe a minimum separation distance of 2' (0.6m) between
modems. Transmitting in close proximity of other modems can damage modem front ends.
3.1. Serial Communications
3.1.1. RS-232 and RS-485/422 Data Flow
The XTend RS-232/422/485 RF Modem interfaces to a host device through a standard DB-9 connector. Devices that have a standard DB-9 (RS-232) serial port can connect directly through the
pins of the modem as shown in the figure below.
Figure 3-01. System Data Flow in an RS-232 environment
3.1.2. Host and RF Modem Settings
Serial communications between a host and an XTend RF Modem are dependent upon having
matching baud rate, parity, stop bit & number of data bits settings. Failure to enter the modem
into AT Command Mode is most co mmonly due to baud r ate mismatc h. Ref er to the table below to
ensure host serial port settings match those of the modem.
Table 3-01. Parameter Values Critical to serial communications between RF Modem and host
Parameter SettingXTend RF Modem Default Parameter Value
Baud (Serial Data Rate)9600 bps (BR parameter = 3)
Number of Data Bits8 (NB parameter = 0)
ParityNone (NB parameter = 0)
Number of Stop Bits1 (NB parameter = 0)
Both the RF modem and host (PC) settings can be viewed and adjusted using Digi's proprietary XCTU Software. After connecting an RF modem to a PC via their respective serial connections, use
the "Terminal" or "Modem Configuration" tabs to configure RF modem settings. Use the "PC Settings" tab to configure host settings.
13
9XTend™ RS-232/422/485 RF Modem User’s Guide
3.1.3. Flow Control
Figure 3-02. Internal Data Flow Diagram (The five most commonly-used pin signals shown)
DI (Data In) Buffer and Flow Control
When serial data enters the modem through the DI pin (Data In), the data is stored in the DI
Buffer until it can be processed.
When the RB and RO parameter thresholds are satisfied (refer to ‘Transmit Mode’ section for mor e
information), the modem attempts to initialize an RF connection. If the modem is already receiving RF data, the serial data is stored in the modem's DI Buffer. The DI buffer stores at least 2.1
KB. If the DI buffer becomes full, hardware or software flow control must be implemented in order
to prevent overflow (loss of data between the host and RF modem).
How to eliminate the need for flow control:
1. Send messages that are smaller than the DI buffer size. The size of the DI buffer varies
according to the packet size (PK parameter) and the parity setting (NB parameter) used.
2. Interface at a lower baud rate (BD parameter) than the RF data rate (BR parameter).
Two cases in which the DI Buffer may become full and possibly overflow:
1. If the serial interface data rate is set higher than the RF data rate of the modem, the
modem will receive data from the host faster than it can transmit the data over-the-air.
2. If the modem is receiving a continuous stream of RF data or if the modem is monitoring
data on a network, any serial data that arrives on the DI pin (Data In) is placed in the DI
Buffer. The data in the DI buffer will be transmitted over-the-air when the modem no
longer detects RF data in the network.
Hardware Flow Control (CTS
the modem de-asserts CTS
(Flow Control Threshold) and CS (GPO1 Configuration) Commands]. CTS
DI Buffer has 34 bytes of memory available.
Software Flow Control (XON). XON/XOFF software flow control can be enabled using the FL
(Software Flow Control) Command. This option only works with ASCII data.
DO (Data Out) Buffer
When RF data is received, the data enters the DO buffer and is sent out the serial port to a host
device. Once the DO Buffer reaches capacity, any additional incoming RF data is lost. The DO
buffer stores at least 2.1 KB.
Two cases in which the DO Buffer may become full and possibly overflow:
1. If the RF data rate is set higher than the interface data rate of the modem, the modem will
receive data from the transmitting modem faster th an it can send the data to the host.
2.If the host does not allow the modem to transmit data out from the DO buffer because of
being held off by hardware or software flow control.
). When the DI buffer is 17 bytes away from being full; by default,
(high) to signal to the host device to stop sending data [refer to FT
is re-asserted after the
Hardware Flow Control (RTS
not be sent out the DO Buffer as long as RTS
Software Flow Control (XOFF). XON/XOFF software flow control can be enabled using the FL
(Software Flow Control) Command. This option only works with ASCII data.
). If RTS is enabled for flow control (RT Parameter = 2), data will
(GPI1) is de-asserted.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
3.1.4. Transparent Operation
By default, XTend RF Modems operate in Transparent Mode. The modems act as a serial line
replacement - all UART data received through the DI pin is queued up for RF transmission. When
RF data is received, the data is sent o u t the DO pin.
When the RO (Packetization Timeout) paramete r threshold is satis fied, the modem attemp ts to initialize an RF transmission. If the modem cannot immediately transmit (for instance, if it is already
receiving RF data), the serial data continues to be stored in the DI Buffer. Data is packetized and
sent at any RO timeout or when the maximum packet size is received.
The modem operates as described above unless the Command Mode Sequence is detected. The
Command Mode Sequence consists of three copies of the command sequence character [CC
parameter] surrounded by the before and after guard times [BT & AT parameters].
If the DI buffer becomes full, hardware or software flow control must be implemented in order to
prevent overflow (loss of data between the host and modem).
3.1.5. API Operation
API (Application Programming Interface) Operation is an alternative to the default Transparent
Operation. The API is frame-based and extends the level to which a host application can interact
with the networking capabilities of the module. When in API mode, all data entering and leaving
the RF modem is contained in frames that define operations or events within the modem.
Transmit Data Frames (received through the DI (Data In) pin) include:
• 16-bit address
Receive Data Frames (sent out the DO (Data Out) pin ) include:
• Showing a received RF packet (16 bits only)
• Response to a TX (Transmit) packet
• Showing events such as hardware reset, watchdog reset, asynchronous events, etc.
The modem will send data frames to the application containing status packets; as well as source,
RSSI and payload information from received data packets.
API operation option facilitates many operations such as the examples cited below:
-> Change destination addresses without having to enter command mode
-> Receive success/failure status of each RF packet
-> Identify the source address of each received packet
To implement API operations, see “API Operation” on page 46.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
3.2. Modes of Operation
XTend RF Modems operate in five modes.
Figure 3-03. Modes of Operation
3.2.1. Idle Mode
When not receiving or transmitting data, the RF modem is in Idle Mode. The modem shifts into the
other modes of operation under the following conditions:
• Transmit Mode (Serial data is received in the DI Buffer)
• Receive Mode (Valid RF data is received through the antenna)
• Sleep Mode (Sleep Mode condition is met)
• Command Mode (Command Mode Sequence is issued)
3.2.2. Transmit Mode
When the first byte of serial data is received from the UART in the DI buffer, the modem attempts
to shift to Transmit Mode and initiate an RF connection with o ther modems. After transmission is
complete, the modem returns to Idle Mode.
RF transmission begins after either of the following criteria is met:
1.RB bytes have been received by the UART and are pending for RF transmission.
[Refer to the RB (Packetization Threshold) Command]
2.At least one character has been received by the UART and is pending for RF tra nsmission;
and RO character times of silence been observed on the UART.
[Refer to the RO (Packetization Timeout) Command]
Figure 3-04. Transmit Mode Data Flow
The character timeout trigger can be
disabled by setting RO to zero. In this
case, transmission will not begin until
RB bytes have been received and are
pending for RF transmission. The RB
parameter may be set to any value
between 1 and the RF packet size [refer
to PK (Max RF Packet Size) parameter],
inclusive. Note that transition to Transmit Mode cannot take place during RF
reception; the RF reception must complete before the radio can trans ition into
Transmit Mode.
If RB or RO conditions are met, the
modem initializes a communications channel. Serial da ta in the DI buffer is grouped into RF packets (up to 2048 bytes in each packet, refer to PK Command), converted to RF data and is transmitted over-the-a ir un til the DI buffer is empty.
16
9XTend™ RS-232/422/485 RF Modem User’s Guide
Channel initialization is the process of sending an RF initializer that synchronizes receiving
modems with the transmitting modem. During channel initialization, incoming serial data accumulates in the DI buffer.
RF data, which includes the payload data, follows the RF initializer. The payload includes up to the
maximum packet size (PK Command) bytes. As the TX modem near s the end of th e tr an smis sion ,
it inspects the DI buffer to see if more data exists to be transmitted. This could be the case if more
than PK bytes were originally pending in the DI buffer or if more bytes arrived from the UART after
the transmission began. If more data is pending, the transmitting modem assembles a subsequent
packet for transmission.
Refer to the ‘RF Communication Modes’ section to view state diagrams that illustrate channel initialization and the sequence of events that follow.
RF Packet
Figure 3-05. RF Packet Components
* When streaming multiple RF packets, the RF Initializer is only sent in front of the first packet.
RF Initializer
An RF initializer is sent each time a new connection sequence begins. The RF initializer contains
channel information that notifies receiving modems of information such as the hopping pattern
used by the transmitting modem. The first transmission always sends an RF initializer.
An RF initializer can be of various lengths depending on the amount of time determined to be
required to prepare a receiving modem. For example, a wake-up initializer is a type of RF initializer
used to wake remote modems from Sleep Mode (Refer to the FH, LH, HT and SM Commands for
more information). The length o f the wake-up initializer should be longer than the length of time
remote modems are in cyclic sleep.
Header
The header contains network addressing information that filters incoming RF data. The receiving
modem checks for matching a Hopping Channel, VID and Destination Address. Data that does not
pass through all three network filter layers is discarded.
Refer to the ‘Addressing’ section of the “RF Communication Modes” chapter for more information.
CRC (Cyclic Redundancy Check)
To verify data integrity and provide built-in error checking, a 16-bit CRC (Cyclic Redundancy
Check) is computed for the transmitted data and attached to the end of each RF packet. On the
receiving end, the receiving modem computes the CRC on all incoming RF data. Received data
that has an invalid CRC is discarded [refer to the ‘Receive Mode’ section].
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9XTend™ RS-232/422/485 RF Modem User’s Guide
3.2.3. Receive Mode
If a modem detects RF data while operating in Idle Mode, the modem transitions to Receive Mode
to start receiving RF packets. Once a packet is received, the modem checks the CRC (cyclic redundancy check) to ensure that the data was transmitted without error. If the CRC data bits on the
incoming packet are invalid, the packet is discarded. If the CRC is valid, the packet proceeds to the
DO Buffer.
Figure 3-06. Receive Mode Data Flow
* Refer to the ‘Address Recognition’ section for more information regarding
address recognition.
The modem returns to Idle Mode
when valid RF data is no longer
detected or after an error is
detected in the received RF data. If
serial data is stored in the DI
buffer while the modem is in
Receive Mode, the serial data will
be transmitted after the modem is
finished receiving data and returns
to Idle Mode.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
3.2.4. Sleep Mode
Software Sleep
Sleep Modes enable the modem to enter states of low-power consumption when not in use. Three
software Sleep Modes are supported:
• Pin Sleep (Host Controlled)
• Serial Port Sleep (Wake on Serial Port activity)
• Cyclic Sleep (Wake on RF activity)
In order to enter Sleep Mode, one of the following conditions must be met (in addition to the
modem having a non-zero SM parameter value):
1.The modem is idle (no data transmission or reception) for the amount of time defined by
the ST (Time before Sleep) parameter. [NOTE: ST is only active when SM = 4-5.]
2.GPI2 (SLEEP) is asserted (only for the ‘Pin Sleep’ option).
When in Sleep Mode, the modem will not transmit or receive data until the modem first transitions
to Idle Mode. All Sleep Modes are enabled and disabled using SM Command. Transitions into and
out of Sleep Modes are triggered by various mechanisms as shown in the table below.
Table 3-02. Summary of Sleep Mode Configurations
Sleep Mode
(Setting)
Pin Sleep
(SM = 1)
Serial Port Sleep
(SM = 2)
Cyclic Sleep
(SM = 4 - 8)
Transition into
Sleep Mode
Assert GPI2 pin - A micro controller can
shut down and wake modems via the
GPI2 pin.
Note: The modem will complete a
transmission or reception before
activating Pin Sleep.
Automatic transition to Sleep Mode
occurs after a user-defined period of
inactivity (no transmitting or receiving of
data).
Period of inactivity is defined by the ST
(Time before Sleep) Command.
RF modem transitions in and out of Sleep Mode in cycles (user-selectable
wake-up interval of time is set using the SM command). The cyclic sleep
interval of time must be shorter than the interval of time that is defined by the
LH (Wake-up Initializer TImer) command .
Note: The modem can be forced into Idle Mode using the GPI2 pin if the PW
(Pin Wake-up) command is issued.
Transition out of Sleep
Mode (wake)
De-assert GPI2 pin(SM)< 17 mA
When a serial byte is received on
the DI pin
Related
Commands
(SM), ST< 45 mA
(SM), ST, HT,
LH, PW
Power
Consumption
< 25 mA
when sleeping
(SM=4, 1 sec.,
@120K baud)
The SM (Sleep Mode) command is central to setting all Sleep Mode configurations. By default,
Sleep Modes are disabled (SM = 0) and the modem remains in Idle/Receive Mode. When in this
state, the modem remains constantly ready to respond to serial or RF activity.
Pin Sleep (SM = 1)
• Pin/Host-controlled
• Typical power-down current: < 17 mA
This mode is voltage level activated. When the GPI2 pin is asserted, the modem will finish any
transmitting or receiving activity; enter Idle Mode; then enter a state of sleep. When in Pin Sleep
Mode, the modem will not respond to serial or RF activity.
After enabling Pin Sleep, the GPI2 pin controls whether the modem is active or sleeping. When
GPI2 is de-asserted, the modem is fully operational. When GPI2 is asserted, the modem transitions to Sleep Mode and remains in its lowest power-consuming state until the pin is de-asserted.
This pin is only active if the modem is setup to operate in this mode; otherwise the pin is ignored.
Once in Pin Sleep, CTS
modem. The PWR pin is also de-asserted (low) when the modem is in Pin Sleep Mode.
Note: The modem will complete a transmission or reception before activating Pin Sleep.
(GPO1) is de-asserted (high), indicating that data should not be sent to the
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Serial Port Sleep (SM = 2)
• Wake on serial port activity
• Typical power-down current: < 45 mA
Serial Port Sleep is a Sleep Mode in which the modem runs in a low power state until serial data is
detected on the DI pin.
The period of time the modem sleeps is determined by ST (Time before Sleep) Command. Once a
character is received through the DI pin, the modem returns to Idle Mode and is fully operational.
Cyclic Sleep (SM = 4-8)
• Typical Power-down Current: < 25 mA (when asleep)
Cyclic Sleep Modes allow modems to periodically wake and check for RF data. The modem wakes
according to the times designated by the Cyclic sleep settings. If the modem detects a wake-up
initializer during the time it is awake, the modem synchronizes with the transmitting modem and
receives data after the wake-up initializer runs its duration. Otherwise, the modem returns to
Sleep Mode and continues to cycle in and out of activity until a wake-up initializer is detected.
While the modem is in Cyclic Sleep Mode, CTS
should not be sent to the modem. When the modem awakens to listen for data, GPO1 is asserted
and any data received on the DI Pin is transmitted. The PWR pin is also de-asserted (low) when
the modem is in Cyclic Sleep Mode.
The modem remains in Sleep Mode for a user-defined period of time ranging from 0.5 seconds to
16 seconds (SM parameters 4 through 8). After this interval of time, the modem returns to Idle
Mode and listens for a valid data packet for 100 ms. If the modem does not detect valid data (on
any frequency), the modem returns to Sleep Mode. If valid data is detected, the modem transitions into Receive Mode and receives the incoming RF packets. The modem then returns to Sleep
Mode after a period of inactivity determined by the ST "Time before Sleep" parameter.
The modem can also be configured to wake from cyclic sleep when the GPI2 pin is de-asserted. To
configure a modem to operat e in th i s m ann e r, PW (Pin Wake-up) Command must be issued. Once
the GPI2 pin is de-asserted, the modem is forced into Idle Mode and can begin transmitting or
receiving data. It remains active until data is no longer detected for the period of time specified by
the ST Command, 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 al l r eceiving modems must wake during the wake-up initializer portion of data transmission in order to be synchronized with the transmitting modem and
receive the data.
(GPO1) is de-asserted (high) to indicate that 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.
Figure 3-07. Correct Configuration (LH > SM):
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.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
3.2.5. Command Mode
To modify or read modem parameters, the modem must first enter into Command Mode (state in
which incoming characters are interpreted as commands). Two command types are supported:
• AT Commands
• Binary Commands
For modified parameter values to persist in the modem registry, changes must be saved to nonvolatile memory using the WR (Write) command. Otherwise, parameters are restored to previously saved values when the modem is powered off and then on again.
AT Command Mode
To Enter AT Command Mode:
1.Send the 3-character command sequence "+++" and observe guard times before and after
the command characters. [refer to ‘Default AT Command Mode Sequence’ below.] The ‘Terminal’ tab (or other serial communications software) of the X-CTU Software can be used to
enter the sequence.
[OR]
2.Assert (low) the CONFIG
pulse the SHDN
[If the modem is mounted to a Digi RS-232/485 Interface Board, the result can be achieved
by pressing the configuration switch down for 2 seconds.]
Default AT Command Mode Sequence (for transition to Command Mode):
• No characters sent for one second [refer to the BT (Guard Time Before) Command]
• Input three plus characters (“+++”) within one second
[refer to the CC (Command Sequence Character) Command.]
• No characters sent for one second [refer to the AT (Guard Time After) Command.]
All of the parameter values in the sequence can be modified to reflect user preferences.
To Send AT Commands:
Send AT commands and parameters using the syntax shown below.
pin and turn the power going to the modem off and back on (or
pin).
Figure 3-08. Syntax for sending AT Commands
To read a parameter value stored in the modem register, leave the parameter field blank.
The preceding example would change the modem’s Destination Address to "0x1F". To store the
new value to non-volatile (long term) memory, the Write (ATWR) command must subsequently be
sent before powering off the modem.
System Response. When a command is sent to the modem, the modem will parse and execute
the command. Upon successful execution of a command, the modem returns an “OK” message. If
execution of a command results in an error, the modem returns an “ERROR” message.
To Exit AT Command Mode:
1.If no valid AT Commands are received within the time specified by CT (Command Mode
Timeout) Command, the modem automatically returns to Idle Mode.
[OR]
2.Send ATCN (Exit Command Mode) Command.
For an example of programming the RF modem using AT Commands and descriptions of each configurable parameter, see “RF Modem Configuration” on page 23.
21
9XTend™ RS-232/422/485 RF Modem User’s Guide
Binary Command Mode
Sending and receiving parameter values using binary commands is the fastest way to change
operating parameters of the modem. Binary commands are used most often to sample signal
strength [refer to DB (Received Signal Strength) parameter] and/or error counts; or to change
modem addresses and channels for polling systems when a quic k response is necessary. Since the
sending and receiving of parameter values takes place through the same serial data path as 'live'
data (received RF payload), interference between the two types of data can be a concern.
Common questions about using binary commands:
• What are the implications of asserting CMD while live data is being sent or received?
• After sending serial data, is there a minimum time delay before CMD can be asserted?
• Is a time delay required after CMD is de-asserted before payload data can be sent?
• How does one discern between live data and data received in response to a command?
The CMD pin (GPI1) must be asserted in order to send binary commands to the modem. The CMD
pin can be asserted to recognize binary commands anytime during the transmission or reception
of data. The status of the CMD signal is only checked at the end of the stop bit as the byte is
shifted into the serial port. The application does not allow control over when data is received,
except by waiting for dead time between bursts of communication.
If the command is sent in the middle of a stream of payload data to be transmitted, the command
will essentially be executed in the order it is received. If the modem is continuousl y receiving data,
the radio will wait for a break in the receiv ed data before ex ecuting the command. The CTS
will frame the response coming from the binary command request [refer to figure below].
A minimum time delay of 100 µs (after the stop bit of the command byte has been sent) must be
observed before the CMD pin can be de-asserted. The command executes after all parameters
associated with the command have been sent. If all parameters are not received within 0.5 seconds, the modem returns to Idle Mode.
Note: When parameters are sent, th ey are two bytes long wi th the l east si gnificant byte sen t first.
Binary commands that return one parameter byte must be written with two parameter bytes.
Commands can be queried for their current value by sending the command logically ORed (bitwise) with the value 0x80 (hexadecimal) with CMD asserted. When the binary value is sent (with
no parameters), the current value of the command parameter is sent back through the DO pin.
Figure 3-09. Binary Command Write then Read
Signal #4 is CMD
Signal #1 is the DI signal
Signal #2 is the DO signal from the radio
Signal #3 is CTS
signal
In this graph, a value was written to a register and then read out to verify it. While
not in the middle of other received data,
note that the CTS
response out of the modem.
IMPORTANT: In order for the modem to recognize a binary command, the RT (GPI1 Configuration)
parameter must be set to one. If binary programming is not enabled (RT parameter value is not equal
to ‘1’), the modem will not recognize that the CMD pin is asserted and therefore will not recognize the
data as binary commands.
For a binary programming example, see “Binary Commands” on page 25 (DT command example
returns two bytes).
signal outlines the data
22
9XTend™ RS-232/422/485 RF Modem User’s Guide
4. RF Modem Configuration
4.1. Automatic DIP Switch Configurations
Each time the RF modem is powered-on, AT commands are sent to the on-board module as dictated by the positions of the DIP switches. DIP switch configurations are sent automatically during
the power-on sequence and affect modem parameter values as shown in the table below.
Figure 4-01. RF Modem DIP Switches
Table 4-01. Power-up Options - Commands sent as result of DIP Switch Settings (SW = DIP Switch)
SwitchesConditionBehaviorCommands Sent During Power-up
Switches 1 & 2
(Restore Defaults /
Serial Interfacing)
Switches 5 & 6
(TX/RX Modes)
If SW1 & SW2 are
ON (up)
If SW1 is ON (up)RS-232 Operation ATCS 0 (RS-232, CTS flow control)
If SW1 is OFF (down)
If SW5 & SW6 are
OFF (down)
If SW5 is OFF (down)
& SW6 is ON (up)
If SW5 is ON (up) &
SW6 is OFF (down)
If SW5 is ON (up) &
SW6 is ON (up)
Restore Defaults
RS-485 or RS-422
Operation
Multipoint Base
Multipoint Remote
Point-to-Point
User Defined
ATRE
ATWR
ATCS 3 (RS-485 or RS-422 Operation)
ATMY 0
ATDT FFFF
ATMT 3
ATAM
ATDT 0
ATMT 0
ATRR A
ATAM
ATDT FFFF
ATMT 3
Processor is disabled and AT Commands are not sent to
the modem (except for CS command as shown below.)
(Restore Defaults)
(Write defaults to non-volatile memory)
(Auto-set MY, MY = unique)
(Destination Address)
(Multi-Transmit option)
(Retries)
(Auto-set MY, MY = unique)
(Destination Address)
(Multi-Transmit option)
IMPORTANT: To avoid overwriting previously stored custom configurations (due to the automatic configurations that take place each time the RF modem is powered-on), it is necessary to disable a processor located inside the modem.
To disable the processor, turn switches 5 and 6 ON (up). When switches 5 and 6 are ON, only the
CS command is sent [refer to table below].
Table 4-02. User Defined Mode (Switches 5 and 6 are ON (up))
Only DIP Switches ON (up)ConditionCommand Sent During Power-up
SW1, SW5 and SW6
SW2, SW5 and SW6
SW5 and SW6 only
Note: The results of SW 2, 5 & 6 ON and SW 5 & 6 ON are the same.
If CS = 0, 1, 2 or 4CS parameter remains the same
If CS = 3ATCS 0(RS-232 operation, CTS flow control)
If CS = 2ATCS 2(GPO1 high)
If CS = 0, 1, 3 or 4ATCS 3(RS-485/422 Operation)
If CS = 2ATCS 2(GPO1 high)
If CS = 0, 1, 3 or 4ATCS 3(RS-485/422 Operation)
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9XTend™ RS-232/422/485 RF Modem User’s Guide
4.2. Programming Examples
Refer to “Command Mode” on page 21 for information regarding entrance into Command Mode,
sending AT commands and exiting Command Mode.
4.2.1. AT Commands
Digi has provided X-CTU software for programming the modem using an extensive list of AT Commands. The X-CTU software provides an interface that is divided into four tabs that facilitate the
following functions:
• PC Settings tab - Setup PC serial port to interface with an RF modem
• Range Test tab - Test RF modem's range in varying environments
• Terminal tab - Configure and read XTend RF modem parameters using AT Commands
Double-click the ‘setup_X-CTU .exe’ fil e that is located o n the Digi CD and under the ‘Downloads’
section of the following web page: www.maxstream.net/helpdesk/download.php. Then follow
the prompts of the installation screens.
PC Settings Tab (X-CTU Software)
As stated in “Serial Communications” on page 13, in order to communicate data to the RF modem
through the PC, the baud (serial data rate), data bit, parity and stop bit settings on the PC serial
port must match those of the modem. The 'PC Settings' tab provides a software user interface that
facilitates the modification of PC serial port setting.
Note: Do not send com-
Note: Do not send commands to the modem
mands to the modem
during flash program-
during flash programming (when parameters
ming (when parameters
are being written to the
are being written to the
modem registry).
modem registry).
Wait for the "OK" sys-
Wait for the "OK" system response that fol-
tem response that follows the ATWR
lows the ATWR
command before enter-
command before entering the next command
ing the next command
or use flow control.
or use flow control.
PC Setup
1.Set the DIP Switch to RS-232 mode. [Switches 1 & 5 are ON (up) and the remaining 4
switches are OFF (down).]
2.Connect the male DB-9 connector of the PC with the female DB-9 connector of the RF
modem using an RS-232 cable.
3.Power the RF modem through the power connector.
4.Go to the PC Settings tab and select parameter values from the drop-down lists that match
the current parameter values of the RF modem.
Figure 4-02. Setup for RF Modem Configurations through X-CTU Software
Terminal Tab (X-CTU Software)
A terminal program has been built into the X -CTU software and is located under the 'Terminal' tab.
The Terminal tab provides an easy-to-use interface for programming the modem.
Multiple AT Commands. Multiple AT commands can be entered on one line with one carriage
return at the end of the line. Each command must be delimited by a comma (spaces in between
are optional). The "AT" prefix is only sent before the first command and should not be included
with subsequent commands in a line.
System Response. When a command is sent to the modem, the modem will parse and execute
the command. Upon successful execution of a command, the modem returns an "OK" message. If
execution of a command results in an error, the modem returns an "ERROR" message.
Restore RF Modem Default Parameters (Using the ‘Termina l’ tab of the X-CTU Software)
Example: Both of the following examples restore the XTend Modem's factory defaults and save
the parameters to non-volatile memory.
Method 1 (One line per command)
24
9XTend™ RS-232/422/485 RF Modem User’s Guide
Send AT Command
+++
ATRE <Enter>
ATWR <Enter>
ATCN <Enter>
Method 2 (Multiple commands on one line)
Send AT Command
+++
ATRE, WR <Enter>
ATCN <Enter>
NOTE: Default parameter values of the RF Modem can also be restored by selecting the 'Restore' button located
on the “Modem Configuration” tab [refer to the example below].
Example: Utilize the X-CTU “Modem Configuration” tab to restore default parameter values.
After establishing a connection between the modem and a PC [refer to the 'Setup' section
above], select the “Modem Configuration” tab of the X-CTU Software.
1. Select the 'Read' button.
2. Select the 'Restore' button.
System Response
OK <CR> (Enter into Command Mode)
OK <CR> (Restore RF modem default parameter values)
OK <CR> (Write to non-volatile memory)
OK <CR> (Exit Command Mode)
System Response
OK <CR> (Enter into Command Mode)
OK <CR> (Execute multiple commands)
OK (Exit AT Command Mode)
4.2.2. Binary Commands
To Send Binary Commands:
Example: Use binary commands to change the RF modem's destination address to 0x1A0D and
save the new address to non-volatile memory.
1.RT Command must be set to '1' in AT Command Mode to enable binary programming.
prefix. Decimal equivalents are designated by a “d” suffix.)
Binary
Command
AT Command NameParameter Range
Command
Category
# Bytes
Returned
Factory
Default
* Firmware version in which command and parameter options were first supported
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9XTend™ RS-232/422/485 RF Modem User’s Guide
4.4. Command Descriptions
Commands in this section are listed alphabetically. Command categories are designated between
the "< >" symbols that follow each command title. By default, XTend RF Modems expect numerical
values in hexadecimal since the default value of the CF (Number Base) Parameter is '1'. Hexadecimal values are designated by the "0x" prefix and decimal values by the "d" suffix.
%V (Board Voltage) Command
<Diagnostics> %V Command is used to read the
current voltage of the modem circuit board.
Sample Output:
5.02 V (when ATCF = 0)
5051F (when ATCF = 1) *
5.02 (when ATCF = 2)
* When CF = 1 (default), a hex integer is shown
that is equal to (voltage * 65536d).
AM (Auto-set MY) Command
<Networking & Security> AM Command is used
to automatically set the MY (Source Address)
parameter from the factory-set serial number of
the modem. The address is formed with bits 29,
28 and 13-0 of the serial number (in that order).
The resulting value is displayed as a result of this command.
AP (API Enable) Command
<Serial Interfacing> The AP command is used to
enable the modem to operate using the framebased API operation.
AT (Guard Time After) Command
AT Command: AT%V
Binary Command: 0x3B (59 decimal)
Parameter Range (read-only):
Number of bytes returned: 4
AT Command: ATAM
Binary Command: 0x40 (64 decimal)
AT Command: ATAP
Parameter Range: 0 - 2
Default Parameter Value:0
Number of Bytes Returned:1
Minimum Firmware Version Required: 2.x20
0x2CCCA - 0x5BFFA
(2.80 - 5.75 decimal)
ParameterConfiguration
0
1
2
API Disabled
(Transparent Operation)
API enabled
(w/out escaped
characters)
API enabled
(with escaped
characters)
<Command Mode Options> A T Comman d is us ed
to set/read the time-of-silence that follows the
command sequence character (CC Command) of
the AT Command Mode Sequence (BT + CC +
AT). By default, 1 second must elapse before and
after the command sequence character.
The times-of-silence surrounding the command
sequence character are used to prevent inadvertent entrance into AT Command Mode.
AT Command: ATAT
Binary Command: 0x05 (5 decimal)
Parameter Range: 2 - (ATST-3), up to 0x7FFC
[x 100 milliseconds]
Default Parameter Value: 0x0A (10 decimal)
Number of bytes returned: 2
Related Commands: BT (Guard Time Before),
CC (Command Sequence Character)
28
9XTend™ RS-232/422/485 RF Modem User’s Guide
BD (Interface Data Rate) Command
<Serial Interfacing> The BD command is used to
set and read the serial interface data rate (baud
rate) used between the RF modem and host. This
parameter determines the rate at which serial
data is sent to the modem from the host. Modified
interface data rates do not tak e effect until the CN
(Exit AT Command Mode) command is issued and
the system returns the 'OK' response.
When parameters 0-8 are sent to the modem, the
respective interface data rates are used (as
shown in the table on the right).
The RF data rate is not affecte d by the BD parameter. If the interface data rate is set higher than
the RF data rate, a flow control configuration may
need to be implemented.
The range between standard and non-standard
baud rates (0x09 - 0x38) is invalid.
Non-standard Interface Data Rates:
Any value above 0x38 will be interpreted as an
actual baud rate. When a value above 0x38 is
sent, the closest interface data rate represented
by the number is stored in the BD register. For example, a rate of 19200 bps can be set by sending the following command line "ATBD4B00". NOTE: When using Digi’s X-CTU Software, non-standard interface data rates can only be set and read using the X- CTU ‘Terminal’ tab. Non-standard
rates are not accessible through the ‘Modem Configuration’ tab.
When the BD command is sent with a non-standard interface data rate, the UART will adjust to
accommodate the requested interface rate. In most cases, the clock resolution will cause the
stored BD parameter to vary from the parameter that was sent (refer to the table below). R eading
the BD command (send "ATBD" command without an associated parameter value) will return the
value actually stored in the modem’s BD register.
Parameters Sent Versus Parameters Stored
BD Parameter Sent (HEX)Interface Data Rate (bps)BD Parameter Stored (HEX)
Non-standard baud rates supported as of
firmware v2.x20
Number of bytes returned: 4
BR (RF Data Rate) Command
<RF Interfacing> The BR command is used to set
and read the RF data rate (rate that RF data is
transmitted over-the-air) of the modem.
AT Command: ATBR
Binary Command: 0x39 (57 decimal)
Parameter Range: 0 - 1
Parameter
09600
1115200
Default Parameter Value:1
Number of bytes returned: 1
Baud (bps)
Configuration
29
9XTend™ RS-232/422/485 RF Modem User’s Guide
BT (Guard Time Before) Command
<AT Command Mode Options> The CC command
is used to set/read the ASCII character used
between guard times of the AT Command Mode
Sequence (BT + CC + AT). This sequence enters
the modem into AT Command Mode so that data
entering the modem (from the host ) is recognized
as commands instead of payload.
CC (Command Sequence Character) Command
<AT Command Mode Options> The CC command
is used to set/read the ASCII character used
between guard times of the AT Command Mode
Sequence (BT + CC + AT). This sequence enters
the modem into AT Command Mode so that data
entering the modem (from the host ) is recognized
as commands instead of payload.
CD (GPO2 Configuration) Command
<Serial Interfacing> CD Command is used to
select/read the behavior of the GPO2 line (pin 3).
CF (Number Base) Command
AT Command: ATCC
Binary Command: 0x13 (19 decimal)
Parameter Range: 0x20 - 0x7F
Default Parameter Value: 0x2B (ASCII “+”)
Number of bytes returned: 1
Related Commands: AT (Guard Time After), BT
(Guard Time Before)
AT Command: ATCC
Binary Command: 0x13 (19 decimal)
Parameter Range: 0x20 - 0x7F
Default Parameter Value: 0x2B (ASCII “+”)
Number of bytes returned: 1
Related Commands: AT (Guard Time After), BT
(Guard Time Before)
AT Command: ATCD
Binary Command: 0x28 (40 decimal)
Parameter Range: 0 - 8 (standard rates)
ParameterConfiguration
0RX LED
1Default High
2Default Low
3(reserved)
4
Default Parameter Value: 2
Number of bytes returned: 1
RX LED
(valid address only)
<Command Mode Options> CF command is used
to set/read the command formatting setting.
The following commands are always entered and
read in hex, no matter the CF setting:
VR (Firmware Version)
HV (Hardware Version)
KY (AES Encryption Key)
AT Command: ATCF
Parameter Range: 0 – 2
ParameterConfiguration
Commands utilize default
0
1
2
Default Parameter Value: 1
Number of bytes returned: 1
number base; decimal
commands may output units
All commands forced to
unsigned, unit-less hex
Commands utilize their
default number base; no
units are output
30
9XTend™ RS-232/422/485 RF Modem User’s Guide
CN (Exit AT Command Mode) Command
<Command Mode Options> The CN command is
used to explicitly exit the modem from AT Command Mode.
CS (GPO1 Configuration) Command
<Serial Interfacing> CS Command is used to
select the behavior of the GP01 pin (pin 9). This
output can provide RS-232 flow control, control
the TX enable signal (for RS-485 or RS-422 operations).
By default, GP01 provides RS-232 CTS
Send) flow control.
CT (Command Mode Timeout) Command
<Command Mode Options> The CT command is
used to set and read the amount of inactive time
that elapses before the modem automatically
exits from AT Command Mode and returns to Idle
Mode.
Use the CN (Exit AT Command Mode) command
to exit AT Command Mode manually.
DB (Received Signal Strength) Command
(Clear-to-
AT Command: ATCN
Binary Command: 0x09 (9 decimal)
AT Command: ATCS
Binary Command: 0x1F (31 decimal)
Parameter Range: 0 - 4
ParameterConfiguration
0RS-232 CTS
1RS-485 TX enable low
2High
3RS-485 TX enable high
4Low
Default Parameter Value: 0
Number of bytes returned: 1
Related Commands: RT (GPI1 Configuration),
TO (GP01 Timeout)
AT Command: ATCT
Binary Command: 0x06 (6 decimal)
Parameter Range: 2 - 0xFFFF
[x 100 milliseconds]
Default Parameter Value: 0xC8 (200d)
Number of bytes returned: 2
Related Command: CN (Exit AT Command
Mode)
flow control
<Diagnostics> DB Command is used to read the
receive signal strength (in decibels relative to milliWatts) of the last received packet. This parameter is useful in determining range characteristics
of the RF modems under various conditions.
In default mode, this command shows the power
level in signed decimal format with the units (dBm). If CF = 1, the magnitude of the value is presented in unsigned hex. If CF = 2, the value is presented in decimal, but without the units.
Sample Output: -88 dBm(when ATCF = 0)
58 (when ATCF = 1)
-88 (when ATCF = 2)
NOTE: If the DB register is read before the modem has received an RF packet, the modem will
return a value of 0x8000 (which means an RF packet has not yet been received).
AT Command: ATDB
Binary Command: 0x36 (54 decimal)
Parameter Range (read-only): 0x6E - 0x28
(-110 to -40 Decimal)
Number of bytes returned: 2
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9XTend™ RS-232/422/485 RF Modem User’s Guide
DT (Destination Address) Command
<Networking & Security> DT Command is used to
set/read the networking address of an RF
modem. The modems utilize three filtration layers: Vendor ID Number (ATID), Channel (ATHP),
and Destination Address (ATDT). The DT command assigns an address to a modem that
enables it to communicate only with other
modems having the same address. All modems
that share the same DT parameter can communicate with each other.
RF modems in the same network with a different destination address (than that of the transmitter)
will listen to all transmissions to stay synchronized, but will not send any of the data out their
serial ports.
E0 (Echo Off) Command
<Command Mode Options> E0 Command turns
off character echo in AT Command Mode.
By default, echo is off.
E1 (Echo On) Command
<Command Mode Options> E1 Command enables
character echo in A T Command Mode. Each typed
character will be echoed back to the terminal
when ATE1 is active. E0 (Echo Off) is the default.
AT Command: ATDT
Binary Command: 0x00
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Related Commands: HP (Hopping Channel), ID
(Modem VID), MK (Address Mask), MY (Source
Address)
AT Command: ATE0
Binary Command: 0x0A (10 decimal)
AT Command: ATE1
Binary Command: 0x0B (11 decimal)
ER (Receive Error Count) Command
<Diagnostics> The ER command is used to set/
read the number of receive-errors. The error
count records the number of packets partially
received then aborted on a reception error. This
value returns to 0 after a reset and is not nonvolatile (Value does not persist in the modem's
memory after a power-up sequence). Once the
Receive Error Count reaches its maximum value
(up to 0xFFFF), it remains at its maximum count
value until the maximum count value is explicitly changed or the modem is reset.
The ER parameter is not reset by pin, serial port or cyclic sleep modes.
FH (Force Wake-up Initializer) Command
<Sleep (Low Power)> The FH command is used
to force a Wake-up Initializer to be sent on the
next transmission. Use only with cyclic sleep
modes active on remote modems.
ATFH will not send a long header if ATHT = 0xFFFF. WR (Write) Command does not need to be
issued with FH Command.
AT Command: ATER
Binary Command: 0x0F (15 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Related Commands: GD (Receive Good Count)
AT Command: ATFH
Binary Command: 0x0D (13 decimal)
32
9XTend™ RS-232/422/485 RF Modem User’s Guide
FL (Software Flow Control) Command
<Serial Interfacing> The FL command is used to
configure software flow control. Hardware flow
control is implemented with the modem as the
GP01 pin (CTS
regulates when serial data can be transferred to
the modem.
FL Command can be used to allow software flow
control to also be enabled. The XON character
used is 0x11 (17 decimal). The XOFF character
used is 0x13 (19 decimal)
FS (Forced Synch Time) Command
<RF Interfacing> The FS command only applies
to streaming data. Normally , only the fi rst pack et
of a continuous stream contains the full RF initializer. The RF modems then remain synchronized
for subsequent packets of the stream. This
parameter can be used to periodically force an RF
initializer during such streaming. Any break in
UART character reception long enough to drain
the DI Buffer (UART receive buffer) and cause a pause in RF data transmission will also cause an
RF initializer to be inserted on the next transmission.
FT (Flow Control Threshold) Command
pin of the OEM RF module), which
AT Command: ATFL
Binary Command: 0x07 (7 decimal)
Parameter Range: 0 - 1
ParameterConfiguration
0
1
Default Parameter Value: 0
Number of bytes returned: 1
AT Command: ATFS
Binary Command: 0x3E (62 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Disable software
flow control
Enable software
flow control
[x 10 milliseconds]
<Serial Interfacing> The FT command is used to
set/read the flow control threshold. When FT
bytes have accumulated in the DI buffer (UART
Receive), CTS
ware flow control character is transmitted.
GD (Receive Good Count) Command
<Diagnostics> The GD command is used to set/
read the count of good received RF packets. Its
parameter value is reset to 0 after every reset
and is not non-volatile (The parameter value does
not persist in the RF modem's memory after a
power-up sequence). Once the "Receive Good
Count" reaches its maximum value (up to
0xFFFF), it remains at its maximum count value
until the maximum count value is manually
changed or the modem is reset.
The GD parameter is not reset by pin, serial port or cyclic sleep modes.
is de-asserted or the XOFF soft-
AT Command: ATFT
Binary Command: 0x24 (36 decimal)
Parameter Range:
0 - (DI buffer size minus 0x11) [Bytes]
Default Parameter Value: DI Buffer size minus
0x11 (17 decimal)
Number of bytes returned: 2
AT Command: ATGD
Binary Command: 0x10 (16 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Related Commands: ER (Receive Error Count)
33
9XTend™ RS-232/422/485 RF Modem User’s Guide
HP (Hopping Channel) Command
<Networking & Security> The HP command is
used to set/read the RF modem's hopping channel
number. A channel is one of three layers of filtration available to the modem.
In order for modems to communicate with each
other, the modems mu st have the same channel
number since each channel uses a different hopping sequence. Different channels can be used to
prevent modems in one network from listening to
transmissions of another.
HT (Time before Wake-up Initializer) Command
<Sleep (Low Power)> The HT command is used
to set/read the time of inactivity (no serial or RF
data is sent or received) before a wake-up initializer is sent by a TX (transmitting) RF modem. The
HT parameter should be set shorter than inactivity timeout [ST Command] time of any RX
(receiving) modems operating in Cyclic Sleep
(SM=4-8). The wake-up initializer sent by the TX
modem instructs all RX modems to remain awake
to receive RF data.
From the RX modem perspective: After HT time
elapses and the inactivity timeout [ST Command]
is met, the RX modem goes into cyclic sleep. In cyclic sleep, the RX modem wakes once per sleep
interval [SM Command] to check for a wake-up initializer. When a wake-up initializer is detected,
the modem stays awake to receive data. The wake-up initialize r must be longer than the cyclic
sleep interval to ensure that sleeping modems detect incoming data.
When HT time elapses, the TX modem knows it needs to send a wake-up Initializer for all RX
modems to remain awake and receive the next transmission.
AT Command: ATHP
Binary Command: 0x11 (17 decimal)
Parameter Range: 0 - 9
Default Parameter Value: 0
Number of bytes returned: 1
Related Commands: ID (Modem VID), DT
(Destination Address), MK (Address Mask)
AT Command: ATHT
Binary Command: 0x03 (3 decimal)
Parameter Range: 0 - 0xFFFF
[x 100 milliseconds]
Default Parameter Value: 0xFFFF (wake-up
initializer will not be sent)
Number of bytes returned: 2
Related Commands: LH (Wake-up Initializer
Timer), SM (Sleep Mode), ST (Time before
Sleep)
HV (Hardware Version) Command
<Diagnostics> The HV command is used to read
the hardware version of the RF modem.
ID (Modem VID) Command
<Networking & Security> The ID command is
used to set/read the VID (Vendor Identification
Number) of the RF modem. RF modems must
have matching VIDs in order to communicate.
<Networking & Security> The KY command is
used to set the 256-bit AES (Advanced Encryption
Standard) key for encrypting/decrypting data.
Once set, the key cannot be read out of the
modem by any means. The entire payload of the
packet is encrypted using the key and the CRC is
computed across the ciphertext. When encryption
is enabled, each packet carries an additional 16
bytes to convey the random CBC Initialization
Vector (IV) to the receiver(s). The KY value may
be “0” or any 256-bit value (= 6 4 hex digits = 32 bytes). An y other v alue, incl uding entering ATKY
by itself with no parameters, causes an error.
A modem with the wrong key (or no key) will receive encrypted data, but the data driven out the
serial port will be meaningless. Likewise, a modem with a key will receive unencrypted data sent
from a modem without a key, but the output will be meaningless. Because CBC mode is utilized,
repetitive data appears differently in different transmissions due to the randomly-generated IV.
LH (Wake-up Initializer Timer) Command
<Sleep (Low Power)> The LH Command is used
to set/read the duration of time during which the
wake-up initializer is sent. When receiving
modems are in Cyclic Sleep Mode, they powerdown after a period of inactivity (as specified by
the ST parameter) and will periodically wake and
listen for transmitted data. In order for the
receiving modems to remain awake, they must
detect ~35ms of the wake-up initializer.
LH Command must be used whenever a receiving
modem is operating in Cyclic Sleep Mode. The
Wake-up Initializer Time must be longer than the cyclic sleep time that [as determined by SM
(Sleep Mode) parameter]. If the wake-up initializer time were less than the Cyclic Sleep interval,
the connection would be at risk of missing the wake-up initializer transmission.
Refer to figures loated under the SM command description to view diagrams of correct and incorrect configurations. The images emphasize that the LH value must be greater than the SM value.
AT Command: ATKY
Binary Command: 0x3C (60 decimal)
Parameter Range:
0 - (any other 64-digit hex valid key)
Default Parameter Value: 0 (disabled)
Number of bytes returned: 2
Number Base: Always Hexadecimal
AT Command: ATLH
Binary Command: 0x0C (12 decimal)
Parameter Range: 0 - 0xFF
[x 100 milliseconds]
Default Parameter Value: 1
Number of bytes returned: 1
Related Commands: HT (Time before Wake-up
Initializer), SM (Sleep Mode), ST (Time before
Sleep)
MD (RF Mode) Command
<Networking & Security> The MD command is
used to select/read the settings that enable the
Polling and Repeater Modes on the modem.
Polling Mode - A ‘Polling Base’ is responsible for
polling remotes. A ‘Polling Remote’ requires a poll
in order to transmit.
Repeater Mode - A ‘Repeater’ re-sends RF data
unless the transmission is addressed to it or if the
transmission has already been detected. A
‘Repeater End Node’ handles repeated messages,
but will not repeat the message over-the-air.
Refer to the Polling and Repeater Mode sections
of the ‘RF Communication Modes’ chapter for
more information.
AT Command: ATMD
Binary Command: 0x31 (49 decimal)
Parameter Range: 0 - 6
ParameterConfiguration
0
1[reserved - not used]
2
3Polling Base
4Polling Remote
5Repeater
6Repeater End Node
Default Parameter Value: 0
Number of bytes returned: 1
Minimum Firmware Version Required: 2.x20
Transparent Operation
(Repeater Base)
[reserved - not used]
35
9XTend™ RS-232/422/485 RF Modem User’s Guide
MK (Address Mask) Command
<Networking & Security> The MK command is
used to set/read the Address Mask of a modem.
All RF data packets contain the Destination
Address of the TX (transmitting) modem. When a
packet is received, the TX modem Destination
Address is logically "ANDed" (bitwise) with the
Address Mask of the RX (receiving) modem. The
resulting value must match the Destination
Address or Address Mask of the RX modem for
the packet to be received and sent out the RX
modem's DO (Data Out) pin. If the "ANDed" value does not match the Destination Address or
Address Mask of the RX modem, the packet is discarded.
Sniffer Mode (when MK = 0): ACK requests are ignored and every RX (receive) frame is sent to
the UART, without regard for repeated frames.
All “0” values are treated as irrelevant values and ignored.
MT (Multi-transmit) Command
<Networking & Security> The MT command is
used to enabled multiple transmissions of RF data
packets. When Multi-transmit Mode is enabled
(MT > 0), packets do not request an ACK
(acknowledgement) from the receiving RF
modem(s). MT takes precedence over RR, so if
both MT and RR are non-zero, then MT+1 packets
will be sent (with no ACK requests).
When a receiving modem receives a packet with
remaining forced retransmissions, it calculates
the length of the packet and inhibits transmission
for the amount of time required for all retransmissions. Thereafter, a random number of delay
slots are inserted between 0 and RN before transmission is allowed from the receiving modem(s).
This prevents all listening modems from transmitting at once upon conclusion of a multiple transmission event (when RN > 0).
NOTE: The actual number of forced transmissions is the parameter value plus one. For example, if
MT = 1, two transmissions of each packet will be sent.
AT Command: ATMK
Binary Command: 0x12 (18 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0xFFFF (65535d)
Number of bytes returned: 2
Related Commands: DT (Destination Address),
HP (Hopping Channel), ID (Modem VID), MY
(Source Address)
AT Command: ATMT
Binary Command: 0x3D (61 decimal)
Parameter Range: 0 - 0xFF
Default Parameter Value:0 (no forced
retransmissions)
Number of bytes returned: 1
Related Commands: Networking (DT, MK, MY,
RN, TT), Serial Interfacing (BR, PK, RB, RO), RF
Interfacing (FS)
MY (Source Address) Command
<Networking & Security> The MY command is
used to set/read the Source Address of the RF
modem.
AT Command: ATMY
Binary Command: 0x2A (42 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0xFFFF (Disabled DT (Destination Address) parameter serves as
both source and destination address.)
Number of bytes returned: 2
Related Commands: DT (Destination Address),
HP (Hopping Channel), ID (Modem VID), MK
(Address Mask)
36
9XTend™ RS-232/422/485 RF Modem User’s Guide
NB (Parity) Command
<Serial Interfacing> The NB command is used to
select/read the parity settings of the RF mo dem
for UART communications.
PB (Polling Begin Address) Command
<Networking & Security> PB command is used to
set/read the modem’s Polling Begin Address - the
first address polled Polling Mode is enabled.
Polling Operations: The ‘Polling Base’ (MD = 3)
cycles through a sequential range of addresses,
polling each ‘Polling Remote’ (MD = 4). The base
then waits for a response & proceeds to the next
‘Polling Remote’. Each ‘Polling Remote’ responds
by sending the data from the Data In buffer following the RB & RO parameters. When the re is no
eligible data to send, the ‘Polling R emote’ will not respond. The ‘P olling Base’ will mov e to the next
address in the polling sequence after a short delay.
48-bit space
Default Parameter Value: 0
Number of bytes returned: 1
AT Command: ATPB
Binary Command: 0x45 (69 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Minimum Firmware Version Required: 2.x20
Related Commands: MD (RF Mode), PE (Polling
End Address), PD (Minimum Polling Delay)
8-bit (no parity or
7-bit (any parity)
PD (Minimum Polling Delay) Command
<Networking & Security> The PD command is
used to set/read Polling Delay (Base, MD=3) or
Polling Timeout (Remote, MD=4).
Polling Delay (Base) is the time between polling
cycles. The Polling Base will start the polling cycle
after sending the first poll. After the polling cycle
has completed, the timer is restarted.
Polling Timeout (Remote) is the amount of time
the remote unit will hold data from the serial port
before discarding it. Data entered within the PD
time of the poll is transmitted and not discarded.
PE (Polling End Address) Command
<Networking & Security> PE command is used to
set/read the modem’s Polling End Address - the
last address polled when Polling Mode is enabled.
Polling Operations: The ‘Polling Base’ (MD = 3)
cycles through a sequential range of addresses,
polling each ‘Polling Remote’ (MD = 4). The base
then waits for a response & proceeds to the next
‘Polling Remote’. Each ‘Polling Remote’ responds
by sending data from the DI buffer following the
RB & RO parameters. When there is no eligible
data to send, the ‘Polling Remote’ will not respond. The ‘Polling Base’ will move to the next
address in the polling sequence after a short delay.
Related Commands: MD (RF Mode), PB (Polling
Begin Address), PE (Polling End Address)
AT Command: ATPE
Binary Command: 0x46 (70 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Minimum Firmware Version Required: 2.x20
Related Commands: MD (RF Mode), PB (Polling
Begin Address), PD (Minimum Polling Delay)
37
9XTend™ RS-232/422/485 RF Modem User’s Guide
PK (Maximum RF Packet Size) Command
<RF Interfacing> The PK command is used to set/
read the maximum size of RF packets transmitted
from an RF modem. The maximum packet size
can be used along with the RB and RO parameters
to implicitly set the channel dwe ll time.
If PK is set above 256 and BR is subsequently
changed to 0, PK will automatically be lowered to
256 and a warning will be raised (refer to the BR
(RF Data Rate) and WN (Warning Data) commands for details).
Changes to the PK parameter may have a secondary effect on the RB (Packetization Threshold) parameter . RB must always be less than or equal to
PK. If PK is changed to a value that is less than the current value of RB, the RB value is automatically lowered to be equal to PK.
* When BR = 0 (9600 baud), the maximum PK value is 0x100 (256d). When BR = 1 (115,200
baud), the maximum PK value is 0x800 (2048d).
PL (TX Power Level) Command
<RF Interfacing> The PL command is used to set/
read the power level at which the RF modem
transmits data
AT Command: ATPK
Binary Command: 0x29 (41 decimal)
Parameter Range: 1 - 0x800 [Bytes]
Default Parameter Value:0x100* or 0x800*
(256 or 2048 decimal)
Number of bytes returned: 2
Related Commands: BR (RF Data Rate) RB
(Packetization Threshold), RO (Packetization
Timeout), WN (Warning Data)
AT Command: ATPL
Binary Command: 0x3A (58 decimal)
Parameter Range: 0 - 4
ParameterConfiguration
01 mW
110 mW
2100 mW
3500 mW
41000 mW (1 Watt)
Default Parameter Value: 4
Number of bytes returned: 1
PW (Pin Wake-up) Command
<Sleep (Low Power)> Under normal operation, an
RF modem in Cyclic Sleep Mode cycles from an
active state to a low-power state at regular intervals until data is ready to be received. If the PW
parameter is set to 1, the GPI2 pin (SLEEP) can
be used to awaken the modem from Cyclic Sleep.
When the GPI2 Pin is de-asserted (low), the
modem will be fully operational and will not go
into Cyclic Sleep.
Once the GPI2 pin is asserted, the modem will
remain active for the period of time specified by
the ST (Time before Sleep) parameter and will
return to Cyclic Sleep Mode (if no data is ready to
be transmitted). PW Command is only valid if Cyclic Sleep has been enabled.
AT Command: ATPW
Binary Command: 0x1D (29 decimal)
Parameter Range: 0 - 1
ParameterConfiguration
0Disabled
1Enabled
Default Parameter Value: 0
Number of bytes returned: 1
Related Commands: SM (Sleep Mode), ST
(Time before Sleep)
38
9XTend™ RS-232/422/485 RF Modem User’s Guide
RB (Packetization Threshold) Command
<Serial Interfacing> The RB command is used to
set/read the character threshold value.
RF transmission begins after data is received in
the DI Buffer and either of the following criteria is
met:
• RB characters received by the UART
• RO character times of silenc e detected on the
UART receive lines (after receiving at least 1
Byte of data)
If PK (Max. RF Packet Size) is lowered below the
value of RB, RB is automatically lowered to match the PK value. If (RO = 0), RB bytes must be
received before beginning transmission.
Note: RB and RO criteria only apply to the first packet of a multi-packet transmission. If data
remains in the DI Buffer after the first packet, transmissions will continue in a streaming manner
until there is no data left in the DI Buffer (UART receive buffer).
RC (Ambient Power - Single Channel) Command
<Diagnostics> The RC command is used to examine and report the power level on a given channel.
Sample output: -78 dBm [when CF = 0]
4e [when CF = 1]
-78 [when CF = 2]
RE (Restore Defaults) Command
AT Command: ATRB
Binary Command: 0x20 (32 decimal)
Parameter Range: 0 - PK parameter value
(up to 0x800 Bytes)
Default Parameter Value: 0x800 Bytes
Number of bytes returned: 2
Related Commands: BR (RF Data Rate), PK (RF
Packet Size), RO (Packetization Timeout)
AT Command: ATRC
Parameter Range (read-only): 0 - 0x31 [dBm]
Number of bytes returned: 1
Related Commands: RM (Ambient Power - All
Channels)
<Diagnostics> The RE command is used to
restore all configurable parameters to their factory default settings.
The RE Command does not cause default values
to be stored to non-volatile (persistent) memory. F or the restored default settings to persist in the
modem’s non-volatile memory and be saved in the event of RF modem reset or power-down, the
WR (Write) command must be issued prior to power-down or reset.
RM (Ambient Power - All Channels) Command
<Diagnostics> The RM command is used to
examine and report power levels on all channels.
If no parameter is given, the channels are
scanned one time. If a parameter is given, the
channels are repeatedly scanned for that number
of seconds. The maximum power level seen for
each channel is reported (i.e. peak hold).
A graphical spectrum analyzer can be implemented by repeatedly sending the RM command (with
no arguments) and reading the resultant 50 power levels (this is easiest to do when CF = 1 or 2).
Sample output [when CF = 0]:Ch 0: -100 dBm
Ch 1: -103 dBm
...
Ch 49: -99 dBm
Sample output [when CF = 1]:64
67
...
63
Sample output [when CF = 2]:100
-103
…
-99
AT Command: ATRE
Binary Command: 0x0E (14 decimal)
AT Command: ATRM
Parameter Range: no parameter - 0x7D0)
Number of bytes returned: 2
Related Commands: RC (Ambient Power Single channel)
39
9XTend™ RS-232/422/485 RF Modem User’s Guide
RN (Delay Slots) Command
<Networking & Security> The RN command is
used to set/read the time dela y that the transmitting RF modem inserts before attempting to
resend a packet. If the transmitting modem fails
to receive an acknowledgement after sending a
packet, it inserts a random number of delay slots
(ranging from 0 to (RN minus 1)) before attempting to resend the packet. Each delay slot is 5
msec (when BR=1) and 54 msec (when BR=0).
If two modems attempt to transmit at the same
time, the random time delay after packet failure allows only one modem to transmit the packet
successfully; while the other m odem waits until the channel available for RF transmissio n.
RN Command is only applicable if retries have been enabled [RR (Retries) Command] or if forced
delays will be inserted into a transmission [TT (Streaming Limit) Command].
RO (Packetization Timeout) Command
<Serial Interfacing> The RO command is used to
set/read the Packetization Timeout setting. RF
transmission begins when data is in the DI buffer
and either of the following criteria are met:
• RO character times of silence on the UART
receive lines (after receiving at least 1 byte)
• RB characters have been received by the
UART
RB and RO criteria only apply to the first packet of
a multi-packet transmission. If data remains in
the DI Buffer (UART receive) after the first packet, transmissions will continue in a streaming
manner until there is no data left in the DI Buffer.
When RO is the transmission-beginning criteria: The actual time between the reception of
the last character from the UART and the beginning of RF transmission will be at least 800 µsec
longer than the actual RO time to allow for transmissio n setup. Additionally, it is subject to 100200 µsec of additional uncertainty, which could be significant for small values of RO at high UART
bit rates.
The correct UART character time (10, 11, or 12 bits) is calculated based on the following criteria:
•1 start bit
• 8 data bits
• 0 or 1 parity bit [as determined by the NB (Parity) Command)
• 1 or 2 stop bits [as determined by SB (Stop Bits) Command]
AT Command: ATRN
Binary Command: 0x19 (25 decimal)
Parameter Range: 0 - 0xFF [38 ms slots]
Default Parameter Value: 0
(no delay slots inserted)
Number of bytes returned: 1
Related Commands: RR (Retries), TT
(Streaming Limit)
AT Command: ATRO
Binary Command: 0x21 (33 decimal)
Parameter Range: 0 - 0xFFFF
[ x UART character times ]
Default Parameter Value: 3
Number of bytes returned: 2
Related Commands: RB (Packetization
Threshold)
40
9XTend™ RS-232/422/485 RF Modem User’s Guide
RP (RSSI PWM Timer) Command
<Diagnostics> RP Command is used to enable a
PWM ("Pulse Width Modulation") output on the
Config/RSSI pin (pin 11 of the OEM RF Module).
The pin is calibrated to show the difference
between received signal strength and the sensitivity level of the RF modem. PWM pulses vary
from zero to 95 percent. Zero percent means the
received RF signal is at or below the published
sensitivity level of the modem .
The following table shows dB levels above sensitivity and PWM values (The total time period of the
PWM output is 8.32 ms. PWM output consists of 40 steps and therefore the minimum step size is
0.208 ms.):
Table 4-04. PWM Values
dBm above sensitivity
1020%
2035%
3050%
A non-zero value defines the time that PWM output is active with the RSSI value of the last
received RF packet. After the set time when no RF pack et s are receiv ed, PWM output is se t low (0
percent PWM) until another RF packet is received. PWM output is also set low at power-up. A
parameter value of 0xFF permanently enables PWM output and always reflects the value of the
last received RF packet.
The Config/RSSI pin is shared between PWM output and Config input. When the modem is powered, the Config pin is an input. During the power-up sequence, if RP parameter is a non-zero
value, the Config pin is configured as an output and set low until the first RF packet is received.
With a non-zero RP parameter, the Config pin is an input for RP ms after power up.
(high period / total period)
AT Command: ATRP
Binary Command: 0x22 (34 decimal)
Parameter Range: 0 - 0xFF
[x 100 milliseconds]
Default Parameter Value: 0x20 (32d)
Number of bytes returned: 1
PWM percentage
RR (Retries) Command
<Networking & Security> The RR command is
used to set/read the maximum number of retries
sent for a given RF packet. When RR Command is
enabled (RR>0), RF packet retries and ACKs
(acknowledgements) are enabled.
Exceptions: If the MT command in enabled
(MT>0) or if a broadcast Destination Address is
used (DT = 0xFFFF); RF packet retries and ACKs are disabled.
After transmitting a packet, the transmitting RF modem waits to receive an acknowledgement
from a receiving modem. If the acknowledgement is not received in the period of time specified by
RN (Delay Slots) Command, the original packet is transmitted again. The RF packet is transmitted
repeatedly until an acknowledgement is received or until the packet is sent RR times.
AT Command: ATRR
Binary Command: 0x18 (24 decimal)
Parameter Range: 0 - 0xFF
Default Parameter Value: 0x0A (10 decimal)
Number of bytes returned: 1
41
9XTend™ RS-232/422/485 RF Modem User’s Guide
RT (GPI1 Configuration) Command
<Serial Interfacing> The RT command is used to
set/read the behavior of the GPI1 pin (GPI1) of
the OEM RF Module. The pin can be configured to
enable binary programming or RTS
SB (Stop Bits) Command
<Serial Interfacing> The SB Command is used to
set/read the number of stop bits in the data
packet.
SH (Serial Number High) Command
flow control.
AT Command: ATRT
Binary Command: 0x16 (22 decimal)
Parameter Range: 0 - 2
ParameterConfiguration
0Disabled
1
2Enable RTS
Default Parameter Value: 0
Number of bytes returned: 1
AT Command: ATSB
Binary Command: 0x37 (55 decimal)
Parameter Range: 0 - 1
ParameterConfiguration
01 stop bit
12 stop bits
Default Parameter Value: 0
Number of bytes returned: 1
Enable Binary
Programming
Flow Control
<Diagnostics> SH Command is used to set/read
the serial number high word of the RF modem.
SL (Serial Number Low) Command
<Diagnostics> SL Command is used to set/read
the serial number low word of the RF modem.
AT Command: ATSH
Binary Command: 0x25 (37 decimal)
Parameter Range (read-only): 0 - 0xFFFF
Default Parameter Value: varies
Number of bytes returned: 2
Related Commands: SL (Serial Number Low)
AT Command: ATSL
Binary Command: 0x26 (38 decimal)
Parameter Range (read-only): 0 - 0xFFFF
Default Parameter Value: varies
Number of bytes returned: 2
Related Commands: SH (Serial Number High)
42
9XTend™ RS-232/422/485 RF Modem User’s Guide
SM (Sleep Mode) Command
<Sleep Mode (Low Power)> The SM Command is
used to set/read the RF modem's Sleep Mode settings that configure the modem to run in states
that require minimal power consumption.
ST (Time before Sleep) Command
AT Command: ATSM
Binary Command: 0x01
Parameter Range: 0 - 8 (3 is reserved)
ParameterConfiguration
0Disabled
1Pin Sleep
2Serial Port Sleep
3[reserved]
Cyclic 1.0 second sleep
4
5Cyclic 2.0 second sleep
6Cyclic 4.0 second sleep
7Cyclic 8.0 second sleep
8Cyclic 16.0 second sleep
Default Parameter Value: 0
Number of bytes returned: 1
Related Commands:
Pin Sleep - PC (Power-up Mode), PW (Pin
Wake-up)
Serial Port Sleep - ST (Time before Sleep)
Cyclic Sleep - ST (Time before Sleep), LH
<Sleep Mode (Low Power)> The ST Command is
used to set/read the period of time (in milliseconds) in which the RF modem remains inactive
before entering Sleep Mode.
For example, if the ST Parameter is set to 0x64
(100 decimal), the modem will enter into Sleep
mode after 10 seconds of inactivity (no transmitting or receiving).
This command can only be used if Cyclic Sleep or
Serial Port Sleep Mode settings have been
selected using SM (Sleep Mode) Command.
TP (Board Temperature) Command
<Diagnostics> TP Command is used to read the
current temperature of the board.
Sample Output: 26 C[when ATCF = 0]
1A [when ATCF = 1]
26 [when ATCF = 2].
AT Command: ATST
Binary Command: 0x02 (2 decimal)
Parameter Range: (ATAT+3) - 0x7FFF
[x 100 milliseconds]
Default Parameter Value: 0x64 (100 decimal)
Number of bytes returned: 2
Related Commands: SM (Sleep Mode), LH
(Wake-up Initializer Timer), HT (Time before
Wake-up Initializer)
AT Command: ATTP
Binary Command: 0x38 (56 decimal)
Parameter Range (read-only): 0- 0x7F
Number of bytes returned: 1
Related Command: WN (Warning Data)
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9XTend™ RS-232/422/485 RF Modem User’s Guide
TR (Transmit Error Count) Command
<Diagnostics> The TR command is used to report
the number of retransmit failures. This number is
incremented each time a packet is not acknowledged within the number of retransmits specified
by the RR (Retries) parameter. The number of
packets therefore are counted that were not successfully received and subsequently d iscarded.
The TR parameter is not non-volatile and is reset
to zero when the RF modem is reset.
TT (Streaming Limit) Command
<Networking & Security> The TT command is
used to set/read the limit on the number of bytes
that can be sent out before a random delay is
issued.
If an RF modem is sendin g a continuous str eam of
RF data, a delay is inserted which sto p s its transmission and allows other modems time to transmit (once it sends TT bytes of data). Inserted
random delay lasts between 1 & 'RN + 1' delay slots, where each delay slot lasts 38 ms.
The TT command can be used to simulate full-duplex behavior.
TX (Transmit Only) Command
<RF Interfacing> The TX command is used to set/
read the transmit/receive behaviors of the RF
modem. Setting a modem to TX-only (TX = 1)
may reduce latency because the transmitting
modem will never be confined to receiving data
from other modems.
AT Command: ATTR
Binary Command: 0x1B (27 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0
Number of bytes returned: 2
Related Commands: RR (Retries)
AT Command: ATTT
Binary Command: 0x1A (26 decimal)
Parameter Range: 0 - 0xFFFF
Default Parameter Value: 0 (disabled)
Number of bytes returned: 2
Related Commands: RN (Delay Slots)
AT Command: ATTX
Binary Command: 0x3F (63 decimal)
Parameter Range: 0 - 1
ParameterConfiguration
0TX & RX
1TX-only
Default Parameter Value: 0
Number of bytes returned: 1
VL (Firmware Version - Verbose)
<Diagnostics> The VL command is used to read
the verbose firmware version of the RF modem.
VR (Firmware Version - Short) Command
<Diagnostics> The VR command is used to read
the firmware version of the RF modem.
Note: Firmware versions contain four significant
digits - “A.B.C.D”. If B=2, the modem is programmed for operation in Australia only.
AT Command: ATVL
Parameter Range: returns string
Default Parameter Value: 0
Number of bytes returned: 2
AT Command: ATVR
Binary Command: 0x14 (20 decimal)
Parameter Range (read-only): 0 - 0xFFFF
Number of bytes returned: 2
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9XTend™ RS-232/422/485 RF Modem User’s Guide
WA (Active Warning Numbers) Command
<Diagnostics> The WA command reports the
warning numbers of all active warnings - one
warning number per line. No further information
is shown and warning counts are not reset.
Sample Output (indicates warnings 1 and 3 are currently active):1
WN (Warning Data) Command
<Diagnostics> WN command is used to report the
following data for all active and sticky warnings:
• Warning number & description
• Number of occurrences since the last WN or WS command
• Whether the warning is currently active
Warnings, which are not currently active and have not been active since the last issuance of the
WN or WS commands, are not displayed. The WN command also resets all non-zero warning
counts; except for warnings that are presently active, which are set to 1.
Sample output: Warning 4: Over-temperature
5 occurrences; presently inactive.
Warning #Description
1
2Over-voltage. This is caused if the supply voltage exceeds 5.75 V. Transmission is not allowed while this warning is active.
3
4
5
6
7
8
Under-voltage. This is caused if the supply voltage falls below the minimum threshold for the lowest power level (2.8 V). If/when the voltage
rises above the threshold, the warning is deactivated. The module will not transmit below this voltage threshold.
Under-temperature. This is caused if the temperature sensed by the module is less than -40 C. The module does not artificially limit operation
while this warning is active, but module functionality is not guaranteed.
Over-temperature. This is caused if the temperature sensed by the module is greater than 105 C. The module does not allow transmission nor
reception while this warning is active. The warning is deactivated when the temperature falls to 100 C.
Power reduced. This is caused if the transmit power has to be reduced from the level programmed by PL Command due to insufficient supply
voltage. The 1 W power level requires 4.75 V or higher; 500 mW requires 3.0 V or higher; 100 mW, 10 mW and 1 mW require 2.8 V or higher.
Default calibration data in flash. This is caused if the module-specific power calibration data is either not present or is invalid, or if none of the
parameters have been modified from their default values. Power levels may be incorrect.
Default configuration parameters in flash. This is cause d if user-modifi able paramete rs (i.e. those s tored by a 'WR' command) in fl ash are all the
compiled-in default values. This is caused if the user configuration is found to be not prese nt or invalid at power-up and there is no custom
configuration, or if no user-modifiable parameters have been modified from the compiled-in defaults. Modification of one or more parameters
without the subsequent WR to commit the changes to flash will not deactivate this warning, since it reflects the status of the parameters in flash.
Note that this warning does not reflect usage of the custom configuration defaults, on ly usage of the compiled-in defaults.
Default factory configuration parameters in flash. This is c aused if the facto ry parameters in flas h are all the def ault values . Th is is caused if the
factory configuration is found to be not present or invalid at power-up, or if no factory parameters have been modified.
AT Command: ATWA
Parameter Range: Returns string - one
warning number per line.
3
OK
AT Command: ATWN
Parameter Range: returns string
WR (Write) Command
<(Special)> The WR command is used to write
configurable parameters to non-volatile memory
(Values remain in the modem's memory until
overwritten by another use of WR Command).
If changes are made without writing them to non-volatile memory, the modem will revert back to
previously saved parameters the next time the modem is powered-on.
If the non-volatile user configuration is not correct, WR will re-attempt (up to 3x). If all three
attempts fail, the command will return an ERROR alert.
WS (Sticky Warning Numbers) Command
<Diagnostics> The WS command reports warning
numbers of all warnings active since the last use
of the WS or WN command (including any warnings which are currently active). This command
also resets all non-zero warning counts, except
for warnings that are presently active, which are set to 1.
AT Command: ATWR
Binary Command: 0x08
AT Command: ATWS
Parameter Range (read-only): 1 - 8
Number of bytes returned: 1
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9XTend™ RS-232/422/485 RF Modem User’s Guide
4.5. API Operation
By default, XTend RF Modems act as a serial line replacement (Transparent Operation) - all UART
data received through the DI pin is queued up for RF transmission. When the modem receives an
RF packet, the data is sent out the DO pin with no additional information.
Inherent to Transparent Operation are the following behaviors:
• If modem parameter registers are to be set or queried, a special operation is required for
transitioning the modem into Command Mode [see p21].
• In point-to-multipoint systems, the application must send extra information so that the
receiving modem(s) can distinguish between data coming from different remotes.
As an alternative to the default Transparent Operation, API (Application Programming Interface)
Operations are available. API operation requires that communication with the modem be done
through a structured interface (data is communicated in frames in a defined order). The API specifies how commands, command responses and modem status messages are sent and received
from the modem using a UART Data Frame.
4.5.1. API Frame Specifications
Two API modes are supported and both can be enabled using the AP (API Enable) command. Use
the following AP parameter values to configure the modem to operate in a particular mode:
• AP = 0 (default): Transparent Operation (UART Serial line replacement)
API modes are disabled.
•AP = 1: API Operation
•AP = 2: API Operation (with escaped characters)
Any data received prior to the start delimiter is silently discarded. If the frame is not received correctly or if the checksum fails, the data is silently discarded.
API Operation (AP parameter = 1)
When this API mode is enabled (AP = 1), th e UART data frame structure is defined as follows:
Figure 4-03. UART Data Frame Structure:
Start Delimiter
(Byte 1)
Length
(Bytes 2-3)
Frame Data
(Bytes 4-n)
Checksum
(Byte n + 1)
0x7EMSBLSBAPI-specific Structure1 Byte
MSB = Most Significant Byte, LSB = Least Significant Byte
API Operation - with Escape Characters (AP parameter = 2)
When this API mode is enabled (AP = 2), the UA RT data frame structure is defined as follows:
Figure 4-04. UART Data Frame Structure - with escape control characters:
Start Delimiter
(Byte 1)
Length
(Bytes 2-3)
Frame Data
(Bytes 4-n)
Checksum
(Byte n + 1)
0x7EMSBLSBAPI-specific Structure1 Byte
Characters Escaped If Needed
MSB = Most Significant Byte, LSB = Least Significant Byte
Escape characters. When sending or receiving a UART data frame, specific data values must be
escaped (flagged) so they do not interfere with the UART or UART data frame oper ation. To escape
an interfering data byte, insert 0x7D and follow it with the byte to be escaped XOR’d with 0x20.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Data bytes that need to be escaped:
• 0x7E – Frame Delimiter
•0x7D – Escape
• 0x11 – XON
• 0x13 – XOFF
Example - Raw UART Data Frame (before escaping interfering bytes):
0x7E 0x00 0x02 0x23 0x11 0xCB
0x11 needs to be escaped which results in the following frame:
0x7E 0x00 0x02 0x23 0x7D 0x31 0xCB
Note: In the above example, the length of the raw data (excluding the checksum) is 0x0002 and
the checksum of the non-escaped data (excluding frame delimiter and length) is calculated as:
0xFF - (0x23 + 0x11) = (0xFF - 0x34) = 0xCB.
Checksum
To test data integrity, a checksum is calculated and verified on non-escaped data.
To calculate: Not including frame delimiters and length, add all bytes keeping only the lowest 8
bits of the result and subtract from 0xFF.
To verify: Add all bytes (include checksum, but not the delimiter and length). If the checksum is
correct, the sum will equal 0xFF.
4.5.2. API Types
Frame data of the UART data frame forms an API-specific structure as follows:
Figure 4-05. UART Data Frame & API-specific Structure:
Start Delimiter
(Byte 1)
0x7E
Length
(Bytes 2-3)
MSBLSB1 Byte
API Identifier
cmdID
Frame Data
(Bytes 4- n)
API-specific Structure
Identifier-specific Data
cmdData
Checksum
(Byte n + 1)
The cmdID frame (API-identifier) indicates which API messages will be contained in the cmdData
frame (Identifier-specific data). Refer to the sections that follow for more information regarding
the supported API types. Note that multi-byte values are sent big endian.
RF Modem Status
API Identifier: 0x8A
RF modem status messages are sent from the modem in response to specific conditions.
Figure 4-06. RF Modem Status Frames
LengthChecksumStart DelimiterFrame Data
MSBLSB0x7E1 ByteAPI-specifi c Structure
Identifier-specific DataAPI Identifier
cmdData0x8A
Status (Byte 5)
0 = Hardware reset
1 = Watchdog ti mer reset
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9XTend™ RS-232/422/485 RF Modem User’s Guide
TX (Transmit) Request: 16-bit address
API Identifier Value: 0x01
A TX Request message will cause the modem to send RF Data as an RF Packet.
Figure 4-7. TX Packet (16-bit address) Frames
LengthChecksu mStart DelimiterF rame Data
MSBLSB0x7E1 ByteAPI- sp ecific Stru ct u re
Identifier-sp ecific DataAPI Identifier
cmdData0x01
Fr ame I D ( B yte 5)
Identifies t he UART data fr am e for the host t o
correlate wit h a subs equent ACK (ack now ledgement).
Setti ng Frame ID to ‘ 0' will dis ab le res ponse frame.
Figure 4-8. Example: TX Packet API Frames
Byte 1
0x7E
Start Delimiter
* Length [Bytes] = API Identifier + Frame ID + Option + RF Data
** “R” value was arbitrarily selected
Bytes 2-3
0x00 0x08
Length*
Byte 4
0x01
API I dentifier
TX (Transmit) Status
API Identifier Value: 0x89
When a TX Request is completed, the modem sends a TX Status message. This message will indicate if the packet was transmitted successfully or if there was a failure.
Figure 4-9. TX Status Frames
Identifies UART data fram e being reported.
Note: I f Frame ID = 0 in th e TX Request, no
AT Comm and Response will be given.
Desti nation A ddress (Bytes 6- 7)
MSB first, LSB last.
Broadcast = 0xFFFF
Byte 5
R (0x52)
Frame ID**
LengthC hecksumStart DelimiterFrame Data
MSBLSB0x7E1 ByteAPI- sp ecific Stru ctu re
Fr ame I D ( B yte 5)Status (B yte 6)
Bytes 6-7
0xFFFF
Destination Address
Identifier-specific DataAPI Identifier
cmdData0x89
Opti o n s (B yte 8)
0 = Standard
1 = D isa ble ACK
Byte 8
0x00
Option
1 (0x31) 2 (0x32) 3 (0x33)
0 = Success
1 = No ACK (Ack now ledgement) r eceived
RF D ata ( B yte( s) 9-n)
Up to 2048 Bytes per packet
Bytes 9-11
RF Data
Checksum
Byte 12
0x18
NOTE: “STATUS = 1” occurs when all retries are expired and no ACK is received.
“STATUS = 3” occurs when a packet is purged due to a ‘Polled Remote’ not receiving a poll.
RX (Receive) Packet: 16-bit address
API Identifier Value: 0x81
When the modem receives an RF packet, it is sent out the UART using this message type.
Figure 4-10. RX Packet (16-bit address) Frames
Source Address (Bytes 5-6)RSSI (Byte 7)
MS B ( m ost signifi cant byte) firs t,
LSB ( least signif icant) last
LengthChecksumStart DelimiterFrame Data
MSBLSB0x7E1 ByteAPI-sp ecific Stru ct u r e
Identifier-specific Dat aAPI Identifier
cmdData0x81
Received Si gnal Strength I ndicator Hexadecimal equivalent of (- dBm) value.
(For example: If RX signal str ength = -40
dBm, “0x28” (40 deci m al) is r etur ned)
Opti o ns (Byte 8)RF D at a (B yt e(s) 9-n)
bit 0 = AC K
bit 1 = Indicate broadcas t
bits 2-7 [ reser ved]
Up to 2048 B ytes per
packet
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5. RF Communication Modes
The network configurations covered in this chapter are described in terms of the following:
• Network Topology (Point-to-Point, Point-to-Multipoint or Peer-to-Peer)
• RF Communication Type (Basic or Acknowledged)
• RF Mode (Streaming, Multi-Transmit, Repeater, Acknowledged or Polling)
The following table provides a summary of the network configurations supported.
Table 5-01. Summary of network topologies supported by the XTend RS-232/422/485 RF Modem
Point-to-Point
DefinitionAn RF data link between two modems.
Sample Network Profile *
RF modems remain synchronized without use of master/server
dependencies. Each modem shares the roles of master and slave.
Digi's peer-to-peer architecture features fast synch ti mes (35ms to
synchronize modems) and fast cold start times (50ms before
transmission).
Use default values for all modems.
All modems:
ATAM [auto-set MY (Source Address) parameter] **
ATDT FFFF [set Destination Address to 0xFFFF]
ATMY 0 [set Source Address t o 0x00]
ATDT FFFF [set Destination Address to 0xFFFF]
ATAM [auto-set MY (Source Address) parameter] **
ATDT 0 [set Destination Add ress to 0x00]
ATMY 0 [set Source Address t o 0x00]
ATDT FFFF [set Destination Address to 0xFFFF]
ATRR 3 [set number of Retries to 3]
ATAM [auto-set MY (Source Address) parameter] **
ATDT 0 [set Destination Add ress to 0x00]
ATRR 3 [set number of Retries to 3]
ATAM [auto-set MY (Source Address) parameter] **
ATDT FFFF [set Destination Address to 0xFFFF]
ATRR 3 [set number of Retries to 3]
* Assume default values for parameters not listed. Profiles do not reflect addressing implementations.
** AM (Auto-set MY) Command must be issued through a terminal program such as the one incorporated in the
X-CTU 'Terminal' tab.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.1. Addressing
Each RF packet contains addressing information that is used to filter incoming RF data. Receiving
modules inspect the Hopping Channel (HP parameter), Vendor Identification Number (ID parameter) and Destination Address (DT parameter) contained in each RF packet. Data that does not pass
through all three network security layers is discarded.
Figure 5-01. Addressing layers contained in the RF packet header
5.1.1. Address Recognition
Transmissions can be addressed to a specific modem or group of modems using the DT (Destination Address) and MK (Address Mask) commands. A receiving modem will only accept a packet if it
determines the packet is addressed to it, either as a global or local packet. The receiving modem
makes this determination by inspecting the destination address of the packet and comparing it to
its own address and address mask [refer to the figure below].
Figure 5-02. Address Recognition (@ the Receiving RF Modem)
TX_DT = Destination Address of transmitting modem
RX_DT = Destination Address of receiving modem
RX_MK = Address Mask of receiving modem
RX_MY = Source Address of receiving modem
The transmitting modem determines whether the packet is intended for a specific node (local
address) or multiple nodes (global address) by comparing the packet's destination address (DT)
and its own address mask (MK) [refer to the figure below]. It is assumed that the address masks
on the transmitting modem and receiving modem have been programmed to the same value for
proper operation in each RF Communication Mode.
Figure 5-03. Address Recognition (@ the Transmitting RF Modem)
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.2. Basic Communications
Basic Communications are accomplished through two sub-types:
• Broadcast - By default, XTend RF Modems communicate through Broadcast communications
and within a peer-to-peer network topology. When any modem transmits, all other modems
within range will receive the data and pass it directly to their host device.
• Addressed - If addressing parameters match are in order, received RF data is forwarded to
the DO (Data Out) buffer; otherwise, the RF data is discarded.
When using Basic Communications, any functions such as acknowledgements are handled at the
application layer by the OEM/integrator. The Broadcast Modes provide transparent communications, meaning that the RF link simply replaces a wired link.
5.2.1. Streaming Mode (Default)
Characteristics:Highest data throughput
Lowest latency and jitter
Reduced immunity to interference
Transmissions never acknowledged (ACK) by receiving module(s)
Required Parameter Values (TX modem): RR (Retries) = 0
Related Commands: Networking (DT, MK, MY), Serial Interfacing (PK, RB, RO, TT)
Recommended Use: Mode is most appropriate for data systems more sensitive to latency and/or
jitter than to occasional packet loss. For example: streaming audio or video.
Connection Sequence
Figure 5-04. Streaming Mode State Diagram (TX Module)
• Events & processes in this mode are common to all of
the other RF Modes.
• When streaming data, RB and RO parameters are only
observed on the first packet.
After transmission begins, the transmission event will continue uninterrupted until the DI buffer is empty or the
streaming limit (TT parameter) is reached. As with the first
packet, the payload of each subsequent packet includes up
to the maximum packet size (PK parameter).
The TT parameter (streaming limit) is specified by the TX
(transmitting) modem as the maxi mum number of bytes the
TX module can send in one tr ansm issi on ev en t. Aft er th e TT
parameter threshold is reached, the TX modem will force a
random delay of 1 to RN delay slots (exactly 1 delay slot if
RN = 0).
Subsequent packets are sent without an RF initializer since
RX (receiving) modems remain synchronized with the TX
modem for the duration of the transmi ssion (from preceding
packet information). However, due to interference, some RX
modems may lose data (and synchronization to the TX
modem), particularly during long transmission events.
Once the TX modem has sent all pending data or has
reached the TT limit, the transmission event ends. The TX
modem will not transmit again for exactly RN delay slots if
the local (i.e. TX modem's) RN parameter is set to a nonzero value. The RX modem(s) will not transmit for a random
number of delay slots between 0 and (RN-1) if the local (i.e.
receiving module's) RN parameter is set to a non-zero
value. These delays are intended to lessen congestion following long bursts of packets from a single TX modem, during which several RX modems may have become ready to transmit.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.2.2. Multi-Transmit Mode
Attributes:Reliable Delivery through forced transmission of every RF packet
Every RF packet is sent exactly (MT + 1) times with no delays between packets
Diminished throughput and increased latency
Required Parameter Values (TX modem): MT (Multi-Transmit) >= 1
Other Related Commands: Networking (DT, MK, MY, RN, TT), Serial Interfacing (BR, PK, RB,
RO), RF Interfacing (FS)
Recommended Use: Use for applications that require Reli able Deli very without using retries and
acknowledgements.
Connection Sequence
Figure 5-05. Multi-Transmit Mode State Diagram
In Multi-Transmit Mode, each packet is
retransmitted MT times, for a total of (MT+1)
transmissions. There is no delay between
retransmissions, and the TX (transmitting)
modem will never receive RF data between
retransmissions. Each retransmission includes
an RF initializer. A transmission event may
include follow-on packets, each of which will be
retransmitted MT times. The Forced Sync (FS)
parameter is ignored in Multi-Transmit Mode.
The RB and RO parameters are not applied to
follow-on packets, meaning that once transmission has begun, it will continue uninterrupted until the DI buffer is empty or the
streaming limit (TT parameter) has been
reached. As with the first packet, the payload
of each follow-on packet includes up to the
maximum packet size (PK parameter) bytes,
and the TX modem checks for more pending
data near the end of each packet. Follow-on
packets are not sent until all retransmissions of
the previous packet are finished.
The streaming limit (TT) is specified at the TX
modem as the maximum number of bytes that
the TX modem can send in one transmission
event, which may consist of many packets. If
the TT parameter is reached, the TX modem
will force a random delay of 1 t o RN delay slots
(exactly 1 delay slot if RN is zero). In MultiTransmit Mode, each packet is counted only
once when tracking the streaming limit (TT),
no matter how many times it is retransmitted.
When an RX (receiving) module receives a
Multi-Transmit packet, it calculates the amount
of time remaining in the Multi-Transmit event,
and inhibits its own transmissions for the duration of the Multi-Transmit event, plus a random
number of delay slots between 0 and (RN-1). If the local RN parameter is zero, the delay is only
for the calculated duration of the Multi-Transmit event. Thus, an RX modem need only receive one
of the transmissions, and it will keep off the channel until the TX modem is done. If follow-on
packets are coming, the RX modems will move to the new frequency and listen for the follow-on
packet for a specific period of time.
(TX Module)
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.2.3. Repeater Mode
Attributes:Low power consumption
Minimized interference
Each RF packet is tagged with a unique Packet ID (PID).
Each repeater will repeat a packet only once (tracked by the PID).
Increased latency and decreased throughput
(Latency and throughput is determined by number of hops, not by number of
repeaters. Multiple repeaters within range of source node count as one hop.)
All RF packets propagate to every modem in the network (filtering rules apply).
Packet destination addresses (DT) determine which packets are sent out serial
port and/or retransmitted.
Broadcast communications - each packet comes out every node exactly once.
Addressed communications - all modems see every packet. Only the modem
with a matching address will forward it to the DO buffer (UART IN).
Constraints:Requires that each modem have a unique MY (Source Address) parameter.
System must introduce just one packe t at a time to the network for tran smission
(Maximum number of bytes is determined by the PK parameter).
Each hop (H) decreases network throughput by a factor of 1/(H+1). Additional
repeaters add network redundancy without decreasing throughput.
Suggestions:Insert a variable delay before repeating packets to avoid collisions
(based on RSSI).
Buffer any incoming serial data and delay response packet transmissions until
previous packet has cleared out of network.
For best results, use the RO and RB commands to ensure that the RF packets
align with the underlying protocol packets as the network can only accept one RF
packet at a time.
Required Parameter Values (TX modem): MD = 5 or 6, MY = unique value (can be accomplished by issuing the AM (Auto-set MY) and WR (Write) commands to all modems in the n etwork)
Related Commands: Networking (MD, DT, MY, AM), Serial Interfacing (RN, PK, RO, RB)
Recommended Use: Use in networks where intermediary modems are needed to relay data to
modems beyond the transmission range of the base modem.
Theory of Operation
OEMs and integrators can extend the effective range and reliability of their data radio system by
forwarding traffic through one or more repeaters. Instead of using routing tables and path discovery to establish dynamic paths through a network, the repeater system uses a sophisticated algorithm to propagate each RF packet through the entire network.
The network supports RF packets up to 2048 bytes (when the RF data rate is set at 9600 bps (BR
= 0)). The repeater network can operate using broadcast or addressed communications for multidrop networks and works well in many systems with no special configuration.
When in Repeater Mode, the network repeats each message among all available modems exactly
one time. This mechanism eliminates the need for configuring specific routes.
Figure 5-06. Repeater Network Topology
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Repeater Network Configuration
A network may consist of End Nodes (EN), End/Repeater No des (ERN) and a Base Node (BN). The
base node initiates all communications.
A repeater network can be configured to operate using Basic Broadcast or Basic Addressed communications. The addressing capabilities of the modem allow integrators to send a packet as a global packet (DT = 0xFFFF) and shift out of every modem in the network (Basic Broadcast).
Alternatively, the packet can be sent with a specific DT (Destination Address) parameter so that it
is only accepted by a specific remote node (Basic Addressed).
Assign each modem a unique MY (source) address. (The AM (Auto-set MY) command will configure a unique source address that is based on modem serial number.)
Enable Basic Broadcast Communications (DT = 0xFFFF) or Addressed Broadcast Communications (DT specifies a specific destination)
Configure PK, RO and RB to ensure that RF packet aligns wit h protocol pac ket. ( ex. PK=0x100,
RB=0x100, RO depends on baud rate).
Configure one or more repeaters in the system (MD = 5).
Configure remote nodes as destinations (MD = 6). This will ensure that the remote node waits
for the repeater traffic to subside before it transmits a response.
The configuration instructions above reflect configuration for a Basic Broadcast Repeater system.
To config ure a Basic Addressed Repeater system, use the DT (Destination Address) parameter to
assign unique addresses to each modem in the network.
Algorithm Details
• Packet ID (PID) is composed of TX (transmitting) modem MY address and packet sequence
number.
• Incoming packets with a PID already found in the PID buffer will be ignored.
• Each modem maintains a PID buffer 4 deep of previously received packets (managed as
FIFO).
Packets may be shifted out the serial port and/or repeated depending on the DT parameter contained in the RF packet.
Table 5-02. DT (Destination Address) parameter truth table
Address MatchSend out serial port?Repeat?
GlobalYesYes
LocalYesNo
NoneNoYes
Repeat Delay Based on RSSI
A transmitted packet may be received by more that one repeater at the same time. In order to
reduce the probability that the repeaters will transmit at the same instant, resulting in a collision
and possible data loss; an algorithm has been developed that will allow a variable back-off prior to
retransmission of the packet by a repeater. The algorithm allows radios that receive the packet
with a stronger RF signal (RSSI) to have the first opportunity to retransmit the packet.
The RN (Delay Slots) parameter is used to configure this delay. Set RN=0 (no delays) for small
networks with few repeaters or repeaters that are not within range of each other. Set RN=1 for
systems with 2 to 5 repeaters that may be within range of each other.
The actual length of the delay is computed by the formula:
Delay (ms) = L * DS
DS = (-41-RSSI)/10*RN)+RandomInt(0,RN)
Where L is the length of the transmitted packe t in mi llis econds, DS is the number of dela y slo ts to
wait, RSSI is the received signal strength in dBm, RN is the value of the RN register and RandomInt(A,B) is a function that returns a random integer from A to B-0
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Response Packet Delay
As a packet propagates through the repeater network, if any node receives the data and generates
a quick response, the response needs to be delayed so as not to collide with subsequent retransmissions of the original packet. To reduce collisions, both repeater and end node radios in a
repeater network will delay transmission of data shifted in the serial port to allow any repeaters
within range to complete their retransmissions.
The time for this delay is computed by the formula:
Maximum Delay (ms) = L * DS
DS = ((-41-(-100))/10)*RN)+RN+1
Where L is the length of the transmitted packe t in mi llis econds, DS is the number of dela y slo ts to
wait, RSSI is the received signal strength in dBm, and RN is the value of the RN register.
Use Case - Broadcast Repeater Network
Consider modems R1 through R10 each communicating to a PLC using the ModBus protocol and
spaced evenly in a line. All ten modems are configured as 'destinations & repeaters' within the
scope of Basic Broadcast Communications (MD=5, AM, DT=0xFFFF, PK=0x100, RO=0x03,
RB=0x100, RN=1). The Base Host (BH) shifts payload that is destined for R10 to R1. R1 initializes
RF communication and transmits payload to nodes R2 through R5 which are all within range of R1.
The modems R2 through R5 receive the RF packet and retransmit the packet simultaneously. They
also send the data out the serial ports, to the PLCs.
Table 5-03. Commands used to configure repeater functions
Using broadcast repeaters in a network reduces the overall network data throughput as each
repeater must buffer an entire packet before retransmitting it. For example: if the destination is
within range of the transmitter and the packet is 32-bytes long, the transmission will take 12ms
on an XTend modem operating at 115,200 baud. If the same packet must propagate through two
repeaters, it will take 12ms to arrive at the first repeater, 12ms to get to the second and a final
12ms to reach the destination for a total of 36ms. Taking into account UART transfer times
(~1ms/byte at 9600 baud), a server to send a 32-byte query and receive a 32-byte response is
about 200ms, allowing for 5 polls per second. With the two repeaters in the path, the same qu ery/
response sequence would take about 500ms for 2 polls per second.
Generally, network throughput will decrease by a factor of 1/(R+1), with R representing the number of repeaters between the source and destination.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.2.4. Polling Mode (Basic)
NOTE: Polling Mode (Basic) and Polling Mode (Acknowledged) [p59] operate in the same way. The
only difference between the two modes is in their means of achieving reliable delivery of data. In
Polling Mode (Basic), reliable delivery is achieved using multiple transmissions.
Attributes:Utilizes high percentage of available network bandwidth
Eliminates collisions
Works with reliable delivery (RR or MT parameters)
Supports binary data transfers
Base modem requests packets from remote modem by polling a sequential
range of addresses
Base modem is configured to specify the range of addresses being polled
Uses inter-character delay to create RF packet lengths aligned with protocol
packet lengths up to 2048 bytes long.
Required Parameter Values (Base): MD (RF Mode) = 3, PB (P ollin g Begin Address), PE (Polling
End Address)
Required Parameter Value (Remote): MD (RF Mode) = 4
Related Commands: Networking (MT, PD, DT, MY, AM)
Constraints: The minimum time interval between polling cycles is configurable. However, if the
remote modems cannot all be processed within that time interval, the polling cycle is ineffective
(i.e. it will impose no additional delay). In order to ensure a pause between polling cycles, PD
must be set to a value which is large enough to accommodate the pause.
Recommended Use: Use for point-to-multipoint applications that require Reliable Delivery of
data. Use this mode when it is critical that a base modem be able to discern data coming from
multiple modems.
Theory of Operation
A ‘Polling Base’ modem will cycle through a sequential range of addresses. The ‘Polling Base’ will
poll each ‘Polling Remote’ modem, wait for a response, then poll the next remote address in the
sequence. Each ‘Polling Remote’ will respond by sending the data from its DI (Data In) buffer following the RB (Packetization Threshold) & RO (Packetization Timeout) parameters. When there is
no eligible data to send, the ‘Polling Remote’ will not respond. The ‘Polling Base’ will poll the next
address in the polling sequence after a short delay.
Polling Base Configuration:
Set the MD (RF Mode) parameter (MD = 3).
Set MY (Source Address) parameter (MY = 0).
Set the sequential range of Polling Addresses using the PB (Polling Begin Address) and PE
(Polling End Address) parameters.
(Optional) Enable Basic Reliable Delivery (MT >= 0). Note: Acknowledged Reliable Delivery is
also supported. Refer to the ‘Polling Mode - Acknowledged’ section for more information.
(Optional) Use the PD (Minimum Polling De lay) command to configure a delay between polls to
slow down system (if needed).
(Optional) Enable API Mode to address remotes within polling range on a packet-by-packet
basis.
Polling Remote Configuration:
Set the MD (RF Mode) parameter (MD = 4).
Configure sequential source addresses for all remote modems using the MY (Source Address)
command.
Set the DT (Destination Address) parameter to point to ‘Polling Base’ (DT = 0x0000).
(Optional) Enable Basic Reliable Delivery (MT >= 0). Note: Acknowledged Reliable Delivery is
also supported. Refer to the ‘Polling Mode - Acknowledged’ section for more information.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.3. Acknowledged Communications
5.3.1. Acknowledged Mode
Attributes:Reliable delivery through positive acknowledgements for each packet
Throughput, latency and jitter vary depending on the quality of the channel and
the strength of the signal.
Required Parameter Values (TX modem): RR (Retries) >= 1
Related Commands: Networking (DT, MK, RR), Serial Interfacing (PK, RN, RO, RB, TT)
Recommended Use: Use for applications that require Reliable Delivery. If messages are smaller
than 256 bytes, use RB and RO commands to align RF packets to application packets.
Connection Sequence
Figure 5-07. Acknowledged Mode State
After sending a packet while in
Acknowledged Mode, the TX (transmitting) modem listens for an ACK
(acknowledgement). If it receives
the ACK, it will either move on to
sending a subsequent packet (if
more transmit data is pending) or
will wait for exactly RN random dela y
slots before allowing another transmission (if no more data is pending
to be transmitted).
If the TX modem does not receive
the ACK within the allotted time, it
will retransmit the packet with a new
RF initializer following the ACK slot.
There is no delay between the first
ACK slot and the first retransmission.
Subsequent retransmissions incur a
delay of a random number of delay
slots, between 0 and RN. If RN is set
to 0 on the TX modem, there are
never any back-off delays between
retransmissions. Note that during
back-off delays, the TX modem will
go into Idle Mode and may receive
RF data. This can have the effect of
increasing the back-off delay, as the
modem cannot return to Transmit (or
retransmit) Mode as long as it is receiving RF data.
After receiving and acknowledging a packet, the RX (receiving) modem will move to the next frequency and listen for either a retransmission or new data for a specific period of time. Even if the
TX modem has indicated that it has no more pending transmit data, it may not have received the
previous ACK, and so may retransmit the packet, possibly with no delay after the ACK slot. In this
case, the RX modem will always de te ct th e imm edi ate re transmission, which will hold off the communications channel and thereby reduce collisions. RX modems acknowledge each retransmission
they receive, but they only pass the first copy of a packet they receive out the UART.
RB and RO parameters are not applied to subsequent packets, meaning that once transmission
has begun, it will continue uninterrupted until the DI buffer is empty or the streaming limit (TT
parameter) has been reached. As with the first packet, the payload of each subsequent packet
includes up to the maximum packet size (PK parameter), and the TX modem checks for more
pending data near the end of each packet.
Diagram (TX modem)
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9XTend™ RS-232/422/485 RF Modem User’s Guide
The TT parameter (streaming limit) specifies the maximum number of bytes that the TX modem
will send in one transmission event, which may consist of many packets and retries. If the TT
parameter is reached, the TX modem will force a random delay of 1 to RN delay slots (exactly 1
delay slot if RN is zero). Each packet is counted only once toward TT, no matter how many times
the packet is retransmitted.
Subsequent packets in Acknowledged Mode are similar to those in Streaming Mode, with the addition of an ACK between each packet, and the possibility of retransmissions. Subsequent packets
are sent without an RF initializer, as the RX modems are already synchronized to the TX modem
from the preceding packet(s) and they remain synchronized for the duration of the transmission
event. Each retransmission of a packet includes an RF initializer.
Once the TX modem has sent all pending data or has reached the TT limit, the acknowledged
transmission event is complet ed. The TX modem will not tr ansmit again for exactly RN dela y slots,
if the local RN parameter is set to a non-zero value. The RX modem will not transmit for a random
number of delay slots between 0 and (RN-1), if the local RN parameter is set to a non-zero value.
These delays are intended to lessen congestion following long bursts of packets from a single TX
modem, during which several RX modems may have themselves become ready to transmit.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
5.3.2. Polling Mode (Acknowledged)
NOTE: Polling Mode (Acknowledged) and Polling Mode (Basic) [p56] operate in the same way . The
only difference between the two modes is in their means of achieving reliable delivery of data. In
Polling Mode (Acknowledged), reliable delivery is achieved using retries and acknowledgements.
Attributes:Utilizes high percentage of available network bandwidth
Eliminates collisions
Works with reliable delivery (RR or MT parameters)
Supports binary data transfers
Base modem requests packets from remote modem by polling a sequential
range of addresses
Base modem is configured to specify the range of addresses being polled
Uses inter-character delay to create RF packet lengths aligned with protocol
packet lengths up to 2048 bytes long.
Required Parameter Values (Base): MD (RF Mode) = 3, PB (P ollin g Begin Address), PE (Polling
End Address)
Required Parameter Values (Remote): MD (RF Mode) = 4
Related Commands: Networking (RR, PD, DT, MY, AM)
Constraints: The minimum time interval between polling cycles is configurable. However, if the
remote modems cannot all be processed within that time interval, the polling cycle is ineffective
(i.e. it will impose no additional delay). In order to ensure a pause between polling cycles, PD
must be set to a value which is large enough to accommodate the pause.
Recommended Use: Use for point-to-multipoint applications that require Reliable Delivery of
data. Use this mode when it is critical that a base modem be able to discern data coming from
multiple modems.
Theory of Operation
A ‘Polling Base’ modem will cycle through a sequential range of addresses. The ‘Polling Base’ will
poll each ‘Polling Remote’ modem, wait for a response, then poll the next remote address in the
sequence. Each ‘Polling Remote’ will respond by sending the data from its DI (Data In) buffer following the RB (Packetization Threshold) & RO (Packetization Timeout) parameters. When there is
no eligible data to send, the ‘Polling Remote’ will not respond. The ‘Polling Base’ will poll the next
address in the polling sequence after a short delay.
Polling Base Configuration:
Set the MD (RF Mode) parameter (MD = 3).
Set MY (Source Address) parameter (MY = 0).
Set the sequential range of Polling Addresses using the PB (Polling Begin Address) and PE
(Polling End Address) parameters.
(Optional) Enable Acknowledged Reliable Delivery (RR >= 0). Note: Basic Reliable Delivery is
also supported. Refer to the ‘Polling Mode - Basic section for more information.
(Optional) Use the PD (Minimum Polling De lay) command to configure a delay between polls to
slow down system (if needed).
(Optional) Enable API Mode to address remotes within polling range on a packet-by-packet
basis.
Polling Remote Configuration:
Set the MD (RF Mode) parameter (MD = 4).
Configure sequential source addresses for all remote modems using the MY (Source Address)
command.
Set the DT (Destination Address) parameter to point to ‘Polling Base’ (DT = 0x0000).
(Optional) Enable Acknowledged Reliable Delivery (RR >= 0). Note: Basic Reliable Delivery is
also supported. Refer to the ‘Polling Mode - Basic section for more information.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Appendix A: Agency Certifications
FCC (United States) Certification
The XTend RS-232/422/485 RF Modem complies with Part 15 of the FCC rules and regulations.
Compliance with the labeling requirements, FCC notices and antenna usage guidelines is required.
In order to operate under Digi’s FCC Certification, OEMs/integrators must comply with the following regulations:
1.The OEM/integrator must ensure that the text provided with this device [Figure A-01] is
placed on the outside of the final product and within the final product operation manual.
2. The XTend RS-232/422/485 RF Modem may only be used with antennas that have been
tested and approved for use with this modem [refer to ‘FCC-approved Antennas’ section].
Labeling Requirements
WARNING: The Original Equipment Manufacturer (OEM) must ensure that FCC labeling
requirements are met. This includes a clearly visible label on the outside of the final
product enclosure that displays the text shown in the figure below.
Figure A-01. Required FCC Label for OEM products containing the XTend RS-232/422/485 RF Modem
Contains FCC ID: OUR-9XTEND
The enclosed device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions: (i.) this device may not cause harmful interference and (ii.) this device must accept any interference received, including interference that may cause undesired operation.
FCC Notices
IMPORTANT: The XTend RS-232/422/485 RF Modem has been certified by the FCC for use with
other products without any further certification (as per FCC section 2.1091). Modifications not
expressly approved by Digi could void the user's authority to operate the equipment.
IMPORTANT: OEMs must test final product to comply with unintentional radiators (FCC section
15.107 & 15.109) before declaring compliance of their final product to Part 15 of the FCC Rules.
IMPORTANT: The RF modem has been certified for remote and base radio applications. If the
modem will be used for portable applications, the device must undergo SAR testing.
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Re-orient or relocate the receiving antenna,
Increase the separation between the equipment and receiver, Connect equipment and receiver to
outlets on different circuits, or Consult the dealer or an experienced radio/TV technician for help.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Limited Modular Approval
Power output is conducted at the antenna terminal and can be adjusted from 1 mill-watt to 1 Watt
at the OEM level. This is an RF modem approved for Limited Modular use operating as a mobile
transmitting device with respect to section 2.1091 and is limited to OEM installation for Mobile and
Fixed applications only. During final installation, end-users are prohibited from access to any programming parameters. Professional installation adjustment is required for setting module power
and antenna gain to meet EIRP compliance for high gain antenna(s).
Final antenna installation and operating configurations of this transmitter including antenna gain
and cable loss must not exceed the EIRP of the configuration used for calculating MPE. Grantee
(Digi) must coordinate with OEM integrators to ensure the end-users and installers of products
operating with the modem are provided with operating instructions to satisfy RF exposure requirements.
The FCC grant is valid only when the device is sold to OEM integrators. Integrators are instructed
to ensure the end-user has no manual instructions to remove, adjust or install the device.
FCC-approved Antennas
WARNING: This device has been tested with Reverse Polarity SMA connectors with the
antennas listed in the tables of this section. When integrated into OEM products, fixed
antennas require installation preventing end-users from replacing them with nonapproved antennas. Antennas not listed in the tables must be tested to comply with FCC
Section 15.203 (unique antenna connectors) and Section 15.247 (emissions).
Fixed Base Station and Mobile Applications
Digi RF Modems are pre-FCC approved for use in fixed base station and mobile applications. When
the antenna is mounted at least 20cm (8") from nearby persons, the application is considered a
mobile application.
Portable Applications and SAR Testing
When the antenna is mounted closer than 20cm to nearby persons, then the application is considered "portable" and requires an additional test be performed on the final product. This test is
called Specific Absorption Rate (SAR) testing and measures th e emissions from the modem and
how they affect the person.
RF Exposure
This statement must be included as a CAUTION statement in OEM produc t manuals.
WARNING: This equipment is approved only for mobile and base station transmitting
devices. Antenna(s) used for this transmitter must be installed to provide a separation
distance of at least 30 cm from all persons and must not be co-located or operating in
conjunction with any other antenna or transmitter.
NOTE: The separation distance indicated in the above is 30 cm, but any distance greater than or
equal to 23 cm can be used (per MPE evaluation).
Antenna Options (1-watt transmit power output or lower)
Table A-01. Half-wave antennas (approved when operating at 1-watt power output or lower)
Part NumberTypeConnectorGainApplication
A09-HSM-7Straight half-waveRPSMA3.0 dBiFixed / Mobile
A09-HASM-675Articulated half-waveRPSMA2.1 dBiFixed / Mobile
A09-HABMM-P6IArticulated half-wave w/ 6" pigtailMMCX2.1 dBiFixed / Mobile
A09-HABMM-6-P6IArticulated half-wave w/ 6" pigtailMMCX2.1 dBiFixed / Mobile
A09-HBMM-P6IStraight half-wave w/ 6" pigtailMMCX2.1 dBiFixed / Mobile
A09-HRSMRight angle half-waveRPSMA2.1 dBiFixed
A09-HASM-7Articulated half-waveRPSMA2.1 dBiFixed
A09-HGGlass mounted half-waveRPSMA2.1 dBiFixed
A09-HATMArticulated half-waveRPTNC2.1 dBiFixed
A09-HHalf-wave dipoleRPSMA2.1 dBiFixed
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Table A-02. Yagi antennas (approved when operating at 1-watt power output or lower)
Part NumberTypeConnectorGainRequired Antenna Cable LossApplication
A09-Y62 Element YagiRPN6.1 dBi0.1 dB*Fixed / Mobile
A09-Y73 Element YagiRPN7.1 dBi1.1 dB*Fixed / Mobile
A09-Y84 Element YagiRPN8.1 dBi2.1 dB*Fixed / Mobile
A09-Y6TM2 Element YagiRPTNC6.1 dBi0.1 dB*Fixed / Mobile
A09-Y7TM3 Element YagiRPTNC7.1 dBi1.1 dB*Fixed / Mobile
A09-Y8TM4 Element YagiRPTNC8.1 dBi2.1 dB*Fixed / Mobile
Table A-03. Omni-directional base station antennas (approved when operating at 1-watt power output or lower)
Part NumberTypeConnectorGainRequired Antenna Cable LossApplication
A09-F0Fiberglass Base StationRPN0 dBi-Fixed
A09-F1Fiberglass Base StationRPN1.0 dBi-Fixed
A09-F2Fiberglass Base StationRPN2.1 dBi-Fixed
A09-F3Fiberglass Base StationRPN3.1 dBi-Fixed
A09-F4Fiberglass Base StationRPN4.1 dBi-Fixed
A09-F5Fiberglass Base StationRPN5.1 dBi-Fixed
A09-F6Fiberglass Base StationRPN6.1 dBi0.1 dB*Fixed
A09-F7Fiberglass Base StationRPN7.1 dBi1.1 dB*Fixed
A09-F8Fiberglass Base StationRPN8.1 dBi2.1 dB*Fixed
A09-W7Wire Base StationRPN7.1 dBi1.1 dB*Fixed
A09-F0Fiberglass Base StationRPSMA0 dBi-Fixed
A09-F1Fiberglass Base StationRPSMA1.0 dBi-Fixed
A09-F2Fiberglass Base StationRPSMA2.1 dBi-Fixed
A09-F3Fiberglass Base StationRPSMA3.1 dBi-Fixed
A09-F4Fiberglass Base StationRPSMA4.1 dBi-Fixed
A09-F5Fiberglass Base StationRPSMA5.1 dBi-Fixed
A09-F6Fiberglass Base StationRPSMA6.1 dBi0.1 dB*Fixed
A09-F7Fiberglass Base StationRPSMA7.1 dBi1.1 dB*Fixed
A09-F8Fiberglass Base StationRPSMA8.1 dBi2.1 dB*Fixed
A09-W7SMWire Base StationRPSMA7.1 dBi1.1 dB*Fixed
A09-F0TMFiberglass Base StationRPTNC0 dBi-Fixed
A09-F1TMFiberglass Base StationRPTNC1.0 dBi-Fixed
A09-F2TMFiberglass Base StationRPTNC2.1 dBi-Fixed
A09-F3TMFiberglass Base StationRPTNC3.1 dBi-Fixed
A09-F4TMFiberglass Base StationRPTNC4.1 dBi-Fixed
A09-F5TMFiberglass Base StationRPTNC5.1 dBi-Fixed
A09-F6TMFiberglass Base StationRPTNC6.1 dBi0.1 dB*Fixed
A09-F7TMFiberglass Base StationRPTNC7.1 dBi1.1 dB*Fixed
A09-F8TMFiberglass Base StationRPTNC8.1 dBi2.1 dB*Fixed
A09-W7TMWire Base StationRPTNC7.1 dBi1.1 dB*Fixed
* FCC regulations stipulate a 36 dBm EIRP power requirement. Users implementing antenna gain greater than 6.0 dB must compensate for the
added gain with cable loss. When operating at 1 W power output, the sum (in dB) of cable loss and antenna gain shall not exceed 6.0 dB.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Table A-04. Mag Mount antennas (approved when operating at 1-watt power output or lower)
Part NumberTypeConnectorGainRequired Antenna Cable LossApplication
* FCC regulations stipulate a 36 dBm EIRP power requirement. Users implementing antenna gain greater than 6.0 dB must compensate for the
added gain with cable loss. When operating at 1 W power output, the sum (in dB) of cable loss and antenna gain shall not exceed 6.0 dB.
Antenna Options (100 mW transmit power output or lower)
Table A-06. Half-wave antennas (approved when operating at 100 mW power output or lower)
Part NumberTypeConnectorGainApplication
A09-QWQuarter-wave wirePermanent1.9 dBiFixed / Mobile
A09-QRAMM3 " Quarter-wave wireMMCX2.1 dBiFixed / Mobile
A09-QSM-3Quarter-wave straightRPSMA1.9 dBiFixed / Mobile
A09-QSM-3HHeavy duty quarter-wave straightRPSMA1.9 dBiFixed / Mobile
A09-QBMM-P6IQuarter-wave w/ 6" pigtailMMCX1.9 dBiFixed / Mobile
A09-QHRNMiniature Helic al Right Angle solderPermanent-1 dBiFixed / Mobile
A09-QHSNMiniature Helical Right Angle solderPermanent-1 dBiFixed / Mobile
A09-QHSM-22" StraightRPSMA1.9 dBiFixed / Mobile
A09-QHRSM-22" Right angleRPSMA1.9 dBiFixed / Mobile
A09-QHRSM-1701.7" Right angleRPSMA1.9 dBiFixed / Mobile
A09-QRSM-3803.8" Right angleRPSMA1.9 dBiFixed / Mobile
A09-QAPM-5205.2" Articulated Screw mountPermanent1.9 dBiFixed / Mobile
A09-QSPM-33" Straight screw mountPermanent1.9 dBiFixed / Mobile
A09-QAPM-33" Articulated screw mountPermanent1.9 dBiFixed / Mobile
A09-QAPM-3H3" Articulated screw mountPermanent1.9 dBiFixed / Mobile
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Table A-07. Yagi antennas (approved when operating at 100 mW power output or lower)
Part NumberTypeConnectorGainApplication
A09-Y62 Element YagiRPN6.1 dBiFixed / Mobile
A09-Y73 Element YagiRPN7.1 dBiFixed / Mobile
A09-Y84 Element YagiRPN8.1 dBiFixed / Mobile
A09-Y94 Element YagiRPN9.1 dBiFixed / Mobile
A09-Y105 Element YagiRPN10.1 dBiFixed / Mobile
A09-Y116 Element YagiRPN11.1 dBiFixed / Mobile
A09-Y127 Element YagiRPN12.1 dBiFixed / Mobile
A09-Y139 Element YagiRPN13.1 dBiFixed / Mobile
A09-Y1410 Element YagiRPN14. 1 dBiFixed / Mobile
A09-Y1412 Element YagiRPN14. 1 dBiFixed / Mobile
A09-Y1513 Element YagiRPN15. 1 dBiFixed / Mobile
A09-Y1515 Element YagiRPN15. 1 dBiFixed / Mobile
A09-Y6TM2 Element YagiRPTNC6.1 dBiFixed / Mobile
A09-Y7TM3 Element YagiRPTNC7.1 dBiFixed / Mobile
A09-Y8TM4 Element YagiRPTNC8.1 dBiFixed / Mobile
A09-Y9TM4 Element YagiRPTNC9.1 dBiFixed / Mobile
A09-Y10TM5 Element YagiRPTNC10.1 dBiFixed / Mobile
A09-Y11TM6 Element YagiRPTNC11.1 dBiFixed / Mobile
A09-Y12TM7 Element YagiRPTNC12.1 dBiFixed / Mobile
A09-Y13TM9 Element YagiRPTNC13.1 dBiFixed / Mobile
A09-Y14TM10 Element YagiRPTNC14.1 dBiFixed / Mobile
A09-Y14TM12 Element YagiRPTNC14.1 dBiFixed / Mobile
A09-Y15TM13 Element YagiRPTNC15.1 dBiFixed / Mobile
A09-Y15TM15 Element YagiRPTNC15.1 dBiFixed / Mobile
IC (Industry Canada) Certification
Labeling Requirements
Labeling requirements for Industry Canada are similar to those of the FCC. A clearly visible label
on the outside of the final product enclosure must display the following text:
Contains Model 9XTend Radio, IC: 4214A-9XTEND
The integrator is responsible for its product to comply with IC ICES-003 & FCC Part 15, Sub. B Unintentional Radiators. ICES-003 is the same as FCC Part 15 Sub. B and Industry Canada accepts
FCC test report or CISPR 22 test report for compliance with ICES-003.
C-TICK (Australia) Certification
Power Requirements
Regulations in Australia stipulate a maximum of 30 dBm EIRP (Effective Isotropic Radiated Power).
The EIRP equals the sum (in dBm) of power output, antenna gain and cable loss and cannot not
exceed 30 dBm.
Figure A-02. EIRP Formula for Australia
NOTE: The maximum EIRP for the FCC (United States) and IC (Canada) is 36 dBm.
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Appendix B: Development Guide
RS-232 Accessories Kit Contents
The accessories listed below are in cluded with X Tend RF Modems that carry the "-RA" suffix on th e
product number. For example: Part number "XT09-PKC-RA" includes the listed accessories and
part number "XT09-PKC-R" does not. The accessories kit includes hardware and software needed
for developing long range wireless links. For testing the modem's range, Digi recommends the
purchase of one RF Modem with the accessories and one without.
Table B-01. Contents of the XTend RS-232/422/485 Accessories Kit
ItemQty. DescriptionPart Number
Quick Start Guide1Familiarizes users with some of the modem’s most important functions.MD0019
CD1Contains documentation, software and tools needed for RF operation.MD0030
XTend-PKG-R™
Power Adapter1Allows Interface Board to be powered by a 110 Volt AC power supplyJP4P2-9V10-6F
RS-232 Cable (6’)1Connects interface board to devices having an RS-232 serial portJD2D3-CDS-6F
1Long Range 900 MHz RF Modem with RPSMA ConnectorXT09-PKG
Connects to the female RS-232 (DB-9) serial connector of the Digi
Interface Board and can be used to configure the modem to function as a
repeater (for range testing)
Connects to the female RS-232 (DB-9) serial connector of the Digi
1
Interface Board and can be used to connect the modem to another DCE
(female DB9) device
1Used to bypass radios to verify serial cabling is functioning properlyJD3D3-CDN-A
Facilitates adapting the DB-9 Connector of the Digi Interface Board to a
1
CAT5 cable (male DB9 to female RJ45)
Facilitates adapting the DB-9 Connector of the Digi Interface Board to a
1
CAT5 cable (female DB9 to female RJ45)
JD2D3-CDL-A
JD2D2-CDN-A
JE1D2-CDA-A
JE1D3-CDA-A
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Adapters
The development kit inc ludes several adapters that facilitate the following functions:
• Performing Range Tests
• Testing Cables
• Connecting to other RS-232 DCE and DTE devices
• Connecting to terminal blocks or RJ-45 (for RS-485/422 devices)
NULL Modem Adapter (male-to-male)
Part Number: JD2D2-CDN-A (Black, DB-9 M-M) The male-to-male NULL modem adapter is
used to connect two DCE devices. A DCE device connects with a straight-through cable to the male
serial port of a computer (DTE).
Figure B-01. Male NULL modem adapter and pinouts
Figure B-02. Example of a Digi Radio Modem (DCE Device) connecting to another DCE device)
NULL Modem Adapter (female-to-female)
Part Number: JD3D3-CDN-A (Gray, DB-9 F-F) The female-to-female NULL modem adapter is
used to verify serial cabling is functioning properly. To test cables, insert the female-to-female
NULL modem adapter in place of a pair of modem assemblies (RS-232 interface board + XTend RF
Modem) and test the connection without modems in the connection.
Figure B-03. Female NULL modem adapter and pinouts
Serial Loopback Adapter
Part Number: JD2D3-CDL-A (Red, DB-9 M-F) The serial loopback adapter is used for range
testing. During a range test, the serial loopback adapter configures the modem to function as a
repeater by looping serial data back into the radio for retransmission.
Figure B-04. Serial loopback adapter and pinouts
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Male DB-9 to RJ-45 Adapter
Part Number: JD2D2-CDN-A (Yellow) This adapter facilitates adapting the DB-9 Connector of
the Digi Interface Board to a CAT5 cable (male DB9 to female RJ45).
Refer to the ‘RS-485 (4-wire) & RS-422 Operation’ sect ions for RS-485/ 422 connection guidelines.
Figure B-05. Male DB-9 to RJ-45 Adapter and pinouts
Female DB-9 to RJ-45 Adapter
Part Number: JD3D3-CDN-A (Green) This adapter Facilitates adapting the DB-9 Connector of
the Digi Interface Board to a CAT5 cable (female DB9 to female RJ45).
Refer to the ‘RS-485 (4-wire ) & RS-422 Oper ation’ se ctions for RS-485/422 conne ction guidelines.
Figure B-6. Female DB-9 to RJ-45 Adapter and pinouts
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Appendix C: Additional Information
5-Year Warranty
WARRANTY PERIOD: Digi warranties hardware Product for a period of five (5) years.
WARRANTY PROCEDURE: Upon return of the hardware Product Digi will, at its option, repair or
replace Product at no additional charge, freight prepaid, except as set forth below. Repair parts
and replacement Product will be furnished on an exchange basis and will be either reconditioned or
new. All replaced Product and parts become the property of Digi. If Digi determines that the Product is not under warranty, it will, at the Customers option, repair the Product using current Digi
standard rates for parts and labor, and return the Product UPS Ground at no charge in or out of
warranty.
Ordering Information
Figure C-01. Divisions of the XTend RF Modem Part Numbers
PKC = Commercial: 0 to 70° C
PKI = Industrial: -40 to 85° C. Embedded RF Module is Conformal Coated
PKT = Tested Industrial: -40 to 85° C. Embedded RF Module
is Conformal Coated & 100% tested
5
Interface
R = RS-232, RS-485/422
U = USB
E = Ethernet
T = Telephone
6
Accessories Package
A = Accessories Package specific to the interface included
(blank) indicates accessories package not included
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9XTend™ RS-232/422/485 RF Modem User’s Guide
Contact Digi
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Documentation: www.maxstream.net/helpdesk/download.php