MaxStream 9XTend-PKG-R User manual
9XTend-PKG-R™ RS-232/485 RF Modem
9XTend-PKG-R RF Modem
Interfacing Protocol
Modem Operation
Modem Configuration
RF Communication Modes
Appendices
Product Manual v1.2.4
For MaxStream part numbers: XT09-PK…-R…
1 Watt Transmit Power, -110 dBm Receiver Sensitivity, 256-bit AES Encryption
355 south, 520 west, suite 180
Lindon, UT 84042
Phone: (801) 765-9885
Fax: (801) 765-9895
rf-xperts@maxstream.net M100171
www.maxstream.net (live chat support) 2005.08.02
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
© 2005 MaxStream, Inc. All rights reserved
Nopartofthecontentsofthismanualmaybetransmittedorreproduced
inanyformorbyanymeanswithoutthewrittenpermissionof
MaxStream,Inc.
XTend™and9XTend‐PKG‐R™areregisteredtrademarksof
MaxStream,Inc.
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‐DistributionsofAESsourcecodeincludetheabovecopyrightnotice,
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Alternatively,providedthatthisnoticeisretainedinfull,thisproduct
maybedistributedunderthetermsoftheGNUGeneralPublicLicense
(GPL),inwhichcasetheprovisionsoftheGPLapplyINSTEADOF
thosegivenabove.
Disclaimer‐ThisAESsoftwareisprovidedʹasisʹwithnoexplicitor
impliedwarrantiesinrespectofitsproperties,including,butnot
limitedto,correctnessand/orfitnessforpurpose.
Technical Support:
Phone: (801) 765-9885
Live Chat: www.maxstream.net
E-Mail: rf-xperts@maxstream.net
©2005MaxStream,Inc.ConfidentialandProprietaryii
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietaryiii
Contents
1. 9XTend-PKG-R™ RF Modem 4
1.1. Features Overview 4
1.1.1. Worldwide Acceptance 4
1.2. Product Overview 5
1.2.1. Specifications 5
1.3. XTend-PKG-R Interface 6
2. Interfacing Protocol 7
2.1. RS-232 Operation 7
2.1.1. DIP Switch Settings & Pin Signals 7
2.1.2. Wiring Diagrams 8
2.2. RS-485 (2-wire) Operation 9
2.2.1. DIP Switch Settings & Pin Signals 9
2.2.2. Wiring Diagram 9
2.3. RS-485 (4-wire) & RS-422 Operation 10
2.3.1. DIP Switch Settings & Pin Signals 10
2.3.2. Wiring Diagrams 10
2.3.3. RS-485/422 Connection Guidelines 11
3. Modem Operation 12
3.1. Serial Communications 12
3.1.1. RS-232 and RS-485/422 Data Flow 12
3.1.2. Host and RF Modem Settings 12
3.1.3. Flow Control 13
3.2. Modes of Operation 14
3.2.1. Idle Mode 14
3.2.2. Transmit Mode 14
3.2.3. Receive Mode 16
3.2.4. Sleep Mode 17
3.2.5. Shutdown 17
3.2.6. Command Mode 18
4. Modem Configuration 20
4.1. Automatic DIP Switch Configurations 20
4.2. Programming Examples 21
4.2.1. AT Commands (Using X-CTU Software) 21
4.2.2. Binary Commands 22
4.3. Command Reference 23
4.4. Command Descriptions 24
5. RF Communication Modes 41
5.1. Addressing Options 41
5.2. Streaming Mode 42
5.2.1. Connection Sequence 42
5.3. Acknowledged Mode 43
5.3.1. Connection Sequence 43
5.4. Multi-Transmit Mode 45
5.4.1. Connection Sequence 45
Appendix A: Agency Certifications 46
FCC Certification 46
Labeling Requirements 46
FCC Notices 46
FCC-Approved Antennas (900 MHz) 48
IC (Industry Canada) Certification 50
Appendix B: Development Guide 51
RS-232 Accessories Kit Contents 51
Adapters 52
Antennas 53
Appendix C: Additional Information 54
1 Year Warranty 54
Ordering Information 54
Contact MaxStream 55
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary4
1. 9XTend‐PKG‐R™RFModem
The 900 MHz XTend RF Modem is MaxStream’s longest range drop-in
wireless solution. Out-of-box, the RF modem is equipped to sustain
long range wireless links between devices. Simply enter serial data into
one modem and the data surfaces on the other end of the wireless link.
The modem transfers a standard asynchronous serial data stream
between two or more modems. Its built-in RS-232, RS-485 and RS-422
interface allows for rapid integration into existing data systems.
1.1. Features Overview
Long Range at a Low Cost
1 Watt Power Output (1 mW – 1 W, selectable)
Range (@ 9600 bps throughput data rate):
•Indoor/Urban: up to 3000’ (900 m)
•Outdoor line-of-sight:
up to 14 miles (22 km) w/ dipole antenna
•Outdoor line-of-sight:
up to 40 miles (64 km) w/ high gain antenna
Range (@ 115200 bps throughput data rate):
•Indoor/Urban: up to 1500’ (450 m)
•Outdoor line-of-sight:
up to 7 miles (11 km) w/ dipole antenna
•Outdoor line-of-sight:
up to 20 miles (32 km) w/ high gain antenna
Receiver Sensitivity: -110 dBm (@ 9600 baud),
–100 dBm (@ 115200 baud)
Advanced Networking & Security
True Peer-to-Peer (no “master” required),
Point-to-Point, Point-to-Multipoint & Multidrop
Retries and Acknowledgements
FHSS (Frequency Hopping Spread Spectrum)
10 hopping channels - each with over 65,000 network addresses available
256-bit AES Encryption (Refer to KY Command [p29] to implement)
Easy-to-Use
No configuration required
Advanced configurations available
through AT & binary Commands
External DIP Switch configurations
7 to 28 V power supply
Continuous RF data stream of up to
115.2 kbps
Transparent Operation – Wireless links
replace serial wires
Software-selectable serial interfacing
MODBUS, , , &
I/O Support
XII™ Interference Immunity
Power-saving Sleep Modes
Streaming, Acknowledged & Multi-
Send RF Communication Options
Free & Unlimited Technical Support
1.1.1. Worldwide Acceptance
FCC Approved (USA - Go to Appendix A [p46] for FCC Requirements)
Systems that contain XTend Modems inherit MaxStream’s FCC Certification
IC Approved (Canada)
ISM (Industrial, Scientific & Medical) license-free 902-928 MHz frequency band
Manufactured under ISO 9001:2000 registered standards
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1.2. Product Overview
The XTend-PKG-R RF Modem comes configured to provide immediate long range wireless links
between devices. The RF modem can be configured for additional functionality through the use of
standard AT and binary commands [Refer to the Command Mode [p18] & Modem Configuration
[p20] sections for programming options].
1.2.1. Specifications
Table1‐01. XTend‐PKG‐RRS‐232/485RFModemSpecifications
XTend-PKG-R 900 MHz RF Modem Specifications
Performance @ 9600 bps Throughput Data Rate @ 115200 bps Throughput Data Rate
Transmit Power Output 1 mW - 1 W (software selectable) 1 mW - 1 W (software selectable)
Indoor/Urban Range Up to 3000’ (900 m) Up to 1500’ (450 m)
Outdoor
RF line-of-sight Range Up to 14 miles (22 km) w/ dipole antenna
Up to 40 miles (64 km) w/ high-gain antenna Up to 7 miles (11 km) w/ dipole antenna
Up to 20 miles (32 km) w/ high-gain antenna
Interface Data Rate
(selectable using BD Command) 1200 - 230400 bps 1200 - 230400 bps
RF Data Rate 10000 bps 125000 bps
Receiver Sensitivity -110 dBm -100 dBm
Power Requirements (refer also to Table 1-02 below)
Receive Current 110 mA 110 mA
16 sec cyclic sleep (SM=8) 20 mA 19 mA
8 sec cyclic sleep (SM=7) 21 mA 19 mA
4 sec cyclic sleep (SM=6) 24 mA 20 mA
2 sec cyclic sleep (SM=5) 30 mA 22 mA
Idle
Currents
1 sec cyclic sleep (SM=4) 39 mA 25 mA
Pin Sleep Power Down 17 mA 17 mA
Serial Port Sleep Power Down 45 mA 45 mA
Networking & Security
Frequency 902-928 MHz ISM Band
RF Transmission FHSS (Frequency Hopping Spread Spectrum)
Modulation FSK (Frequency Shift Keying)
Supported Network Topologies Peer-to-Peer, Point-to-Point, Point-to-Multipoint & Multidrop
Channel Capacity 10 hop sequences share 50 frequencies
Encryption 256-bit AES Encryption – Refer to KY Command [p29] to implement
Physical Properties
Size 2.750” x 5.500” x 1.125” (6.99cm x 13.97” x 2.86cm)
Weight 7.1 oz. (200g)
Serial Connector DB-9
Operating Temperature -40 to 85º C (industrial)
Antenna
Connector RPSMA (Reverse-polarity SMA)
Type ½ wave dipole whip, 6.75” (17.15 cm), 2.1 dBi Gain
Impedance 50 ohms unbalanced
Certifications (visit www.maxstream.net for complete list)
FCC Part 15.247 OUR-9XTEND
Industry Canada (IC) 4214A-9XTEND
Table1‐02. XTendRFModemSpecifications–Relativetouser‐selectedTXPowerOutput
Power Requirements (TX currents relative to each TX Power Output option)
Transmit Power Output 1 mW 10 mW 100 mW 500 mW 1 W
Transmit Current @9600 baud
(9 VDC supply voltage, typical) 110 mA 145 mA 250 mA 510 mA 900 mA
Transmit Current @115K baud
(9 VDC supply voltage, typical) 110 mA 140 mA 245 mA 500 mA 800 mA
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1.3. XTend-PKG-R Interface
1-01a. Config (Configuration) Switch
Figure1‐01. FrontView
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 and pulses off briefly during RF transmission)
1-01c. Serial Port
Standard female DB-9 (RS-232) DCE connector – 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 the difference between the incoming
signal strength and the modem’s receiver sensitivity.
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.
1-02a. DIP Switch
The Configuration Switch provides an alternate method for
entering into Command Mode. To enter Command Mode at the
default RF data rate of the RF modem, depress the Config
Switch for two seconds.
1‐01c.SerialPort
1‐01d.RSSILEDs
1‐01b.I/O&PowerLEDs
1‐01e.PowerConnector*
1‐01a.ConfigSwitch
*Note:TheXTendRFModemcanaccept
voltagesaslowas5(±5%)V.
ContactMaxStreamtechnicalsupport
(801)765‐9885toimplementthisoption.
Figure1‐02. BackView
1-02b. Antenna Port
Port is a 50ΩRF signal connector for connecting to an external
antenna. The connector type is RPSMA (Reverse Polarity SMA)
female. The connector has threads on the outside of a barrel and a
male center conductor.
During the power-on sequence, the DIP Switch automatically
configures the XTend Modem to operate in different modes.
Each time the RF modem is powered-on, intelligence inside the
XTend RF Modem programs the modem according to the
positions of the DIP Switch. [Refer to Figure 1-03 for DIP
Switch settings].
1‐02a.DIPSwitch
1‐02b.AntennaPort
Figure1‐03. DIPSwitchSettings
Refertotableinthe
“AutomaticDIPSwitch
Configurations”section
[p20]forinformationabout
configurationstriggeredby
theDIPSwitch.
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary7
2. InterfacingProtocol
The XTend-PKG-R 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 & Pin Signals
Figure2‐01.Figure2‐02.
RS‐232DIPSwitchSettingsPinsusedonthefemaleRS‐232(DB‐9)
SerialConnector
DIPSwitchsettingsarereadandapplied
onlywhilepowering‐on.
Table2‐01. RS‐232SignalsandtheirimplementationsontheXTendRFModem
(Low‐assertedsignalsaredistinguishedbyhorizontallineoverpinname.)
DB-9 Pin RS-232
Name
Pin
Reference
Name* Description Implementation
1 DCD
GPO2 /
RX LED Data-Carrier-Detect Connected to DSR (pin6)
2 RXD DO Received Data Serial data exiting the RF Modem (to host)
3 TXD DI Transmitted Data Serial data entering into the RF modem (from host)
4 DTR GPI2 / SLEEP Data-Terminal-Ready Can enable POWER-DOWN on the RF Modem
5 GND - Ground Signal Ground
6 DSR
GPO2 /
RX LED Data-Set-Ready Connected to DCD (pin1)
7 / CMD GPI1 / /
CMD Request-to-Send Provides flow control or
enables “Command Mode” on the RF Modem
8 GPO1 / /
RS-485 TX EN Clear-to-Send Provides
flow control
9 RI - Ring Indicator
Optional power input that is connected internally to the
positive lead of the front power connector
*ThePinReferenceNameprovidesanassociativetagthatreferencescommandsusedtodefinepinbehavior.
GPIstandsfor“GeneralPurposeInput”andGPOstandsfor“GeneralPurposeOutput”.Forexample,theCD
CommandisusedtodefinethebehaviorofGPIO2(pin1).
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©2005MaxStream,Inc.ConfidentialandProprietary8
2.1.2. Wiring Diagrams
RS-232 DTE Device to a DCE RF Modem
Figure2‐03.RS‐232DTE(maleconnector)devicewiredtoanXTendRFModem(femaleconnector)
DCE RF Modem to an RS-232 DCE Device
Figure2‐04.XTendRFModem(femaleconnector)wiredtoanRS‐232DTE(maleconnector)device
Sample Wireless Connection: DTE ÙDCE DCE ÙDCE
Figure2‐05.TypicalwirelessconnectionusedforserialcommunicationsbetweenDTEandDCEdevices
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
2.2. RS-485 (2-wire) Operation
2.2.1. DIP Switch Settings & Pin Signals
Figure2‐06.Figure2‐07.
RS‐485(2‐wire)Half‐DuplexPinsusedonthefemaleRS‐232(DB‐9)
DIPSwitchSettingsSerialConnector
Figure2‐08.
RS‐485(2‐wire)withTermination(optional)
Terminationisthe120ΩresistorbetweenT+andT‐.
DIPSwitchsettingsarereadandappliedonlywhilepowering‐on.
Note: Refer to Figures 2-15 and 2-16 for RJ-45 connector pin designations used in
RS-485/422 environments.
Table2‐02. RS‐485(2‐wirehalf‐duplex)SignalsandtheirimplementationsontheXTendRFModem
DB-9 Pin RS-485 Name Description Implementation
2 T/R- (TRA) Negative Data Line Transmit serial data to and from the
XTend RF Modem
5 GND Ground Signal Ground
8 T/R+ (TRB) Positive Data Line Transmit serial data to and from the
XTend RF Modem
9 PWR Power Optional power input that is connected internally
to the front power connector
1, 3, 4, 6, 7 not used
2.2.2. Wiring Diagram
RS-485 (2-wire) Half-Duplex
Figure2‐09.XTendRFModeminanRS‐485(2‐wire)half‐duplexenvironment
©2005MaxStream,Inc.ConfidentialandProprietary9
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
2.3. RS-485 (4-wire) & RS-422 Operation
2.3.1. DIP Switch Settings & Pin Signals
Figure2.10.Figure2.11.
RS‐485(4‐wire)andRS‐422PinsusedonthefemaleRS‐232(DB‐9)
DIPSwitchSettingsSerialConnector
Figure2.12.
RS‐485(4‐wire)&RS‐422withTermination(optional)
Terminationisthe120ΩresistorbetweenT+andT‐.
DIPSwitchsettingsarereadandappliedonlywhilepowering‐on.
Table2‐03. RS‐485/422(4‐wire)SignalsandtheirimplementationswiththeXTend‐PKG‐RRFModem
DB-9 Pin RS-485/422
Name Description Implementation
2 T- (TA)
Transmit Negative
Data Line Serial data sent from the XTend RF Modem
3 R- (RA)
Receive Negative
Data Line Serial data received by the XTend RF Modem
5 GND Signal Ground Ground
7 R+ (RB)
Receive Positive
Data Line Serial data received by the XTend RF Modem
8 T+ (TB)
Transmit Positive
Data Line Serial data sent from the XTend RF Modem
9 PWR Power Optional power input that is connected internally
to the front power connector
1, 4, 6 not used
2.3.2. Wiring Diagrams
RS-485 (4-wire) Half-Duplex
Figure2‐13.XTendRFModeminanRS‐485(4‐wire)environment
©2005MaxStream,Inc.ConfidentialandProprietary10
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary11
RS-422
Figure2‐14.XTendRFModeminanRS‐485(4‐wire)environment
2.3.3. 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 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.
Figure2‐15.MaleDB‐9toRJ‐45Adapter(yellow)
Figure2‐16.FemaleDB‐9toRJ‐45Adapter(green)
An XTend RF Modem Accessories Kit is available that includes connectors that facilitate RS-485/422
and other serial communications. Refer to the Development Guide in Appendix B for information
concerning the connectors and tools included in the kit.
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary12
3. ModemOperation
WARNING: When operating at 1 Watt power output, observe a minimum separation distance of 2’ (0.6 m) 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-PKG-R RF Modem interfaces to a host device through a standard RS-232 (DB-9)
connector. Devices that have a standard RS-232 serial port can connect directly through the pins
of the XTend RF Modem as shown in the figure below.
Figure3‐01. SystemDataFlowinanRS‐232environment
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. Refer to the table below to
ensure host serial port settings match those of the XTend RF Modem.
Table3‐01. ParametervaluescriticaltoserialcommunicationsbetweentheRFModemandhost
Parameter Setting XTend RF Modem Default Parameter Value
Baud (Serial Data Rate) 9600 bps (BR parameter = 3)
Number of Data Bits 8 (NB parameter = 0)
Parity None (NB parameter = 0)
Number of Stop Bits 1 (NB parameter = 0)
Both the XTend RF Modem and host (PC) settings can be viewed and adjusted using MaxStream’s
proprietary X-CTU Software. Use the “Terminal” or “Modem Configuration” tabs to configure the
RF Modem settings. Use the “PC Settings” tab to configure host settings. Refer to the Advanced
Programming and X-CTU Software sections for more information.
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3.1.3. Flow Control
Figure3‐02. InternalDataFlowDiagram
DI (Data In) Buffer and Flow Control
When serial data enters the XTend Modem through the DI Pin, the data is stored in the DI Buffer
until it can be transmitted.
When the RB and RO parameter thresholds are satisfied (refer to Transmit Mode section [p14] for
more 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 XTend 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 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 ( ). When the DI buffer is 17 bytes away from being full; by
default, the modem de-asserts (high) to signal to the host device to stop sending data [refer
to FT (Flow Control Threshold, p28) and CS (GPO1 Configuration, p26) Commands.]. is re-
asserted after the 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 [p27]. This option only works with ASCII data.
DO (Data Out) Buffer & Flow Control
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 than 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.
Hardware Flow Control ( ). If is enabled for flow control (RT Parameter = 2, p35), data
will not be sent out the DO Buffer as long as is de-asserted.
Software Flow Control (XOFF). XON/XOFF software flow control can be enabled using the FL
(Software Flow Control) Command [p27]. This option only works with ASCII data.
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3.2. Modes of Operation
XTend RF Modems operate in five modes.
Figure3‐03. ModesofOperation
TheRFmodemcanonlybeinonemodeatatime.
3.2.1. Idle Mode
When not receiving or transmitting data, the modem is in Idle Mode. The modem uses the same
amount of power in Idle Mode as it does in Receive Mode.
The modem shifts into the other modes of operation under the following conditions:
•Serial data is received in the DI Buffer (Transmit Mode)
•Valid RF data is received through the antenna (Receive Mode)
•Command Mode Sequence is issued (Command Mode)
•Sleep Mode condition is met (Sleep Mode)
The modem automatically transitions to Idle Mode after responding to these conditions.
3.2.2. Transmit Mode
When the first byte of serial data is received from the host in the DI buffer, the modem attempts
to shift to Transmit Mode and initiate an RF connection with other modems. After transmission is
finished, 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 host and are pending for RF transmission.
[RB (Packetization Threshold) Command]
2. At least one character has been received by the host and is pending for RF transmission, and
RO character times of silence have been observed on the host.
[RO (Packetization Timeout) Command]
Figure3‐04. TransmitModeDataFlow
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 (PK),
inclusive. Note that transition to
Transmit Mode cannot take place
during RF reception; the RF
reception must complete before
the modem can transition into
Transmit Mode.
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
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After either of the RB and RO conditions are met, the modem then initializes a communications
channel. Serial data in the DI buffer is grouped into RF packets (up to 2048 bytes in each packet
- refer to PK (Maximum RF Packet Size) Command), converted to RF data and then is transmitted
over-the-air until the DI buffer is empty.
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 nears the end of the
transmission, 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 host during transmission. If more data is pending, the transmitting modem instructs all
listening modems that a subsequent packet is coming. Receiving modems move to the new
frequency and listen for the subsequent packet.
Refer to the RF Communication Options [p41] section for information and state diagrams that
illustrate channel initialization and the sequence of events that follow.
RF Packet
Figure3‐05. RFPacketComponents
*WhenstreamingmultipleRFpackets,theRFInitializerisonlysentinfrontofthefirstpacket.
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. Channel initialization takes 5 ms at the 115k RF data rate and
54 ms at the 9600 RF data rate. 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 of 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 security layers is discarded.
Figure3‐06. NetworkLayersContainedintheHeader
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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 before
transmission. 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].
3.2.3. Receive Mode
If a modem detects RF data while in Idle Mode, the modem transitions into Receive Mode to start
receiving RF packets. Once a packet is received, it goes through the receiving end of a 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 is
placed the DO Buffer.
Figure3‐07. ReceiveModeDataFlow
*RefertotheAddressingOptionssection(undertheRFCommunicationOptionschapter)formoreinformation
aboutaddressrecognition.
The modem returns to Idle Mode after valid RF data is no longer detected or after an error is
detected within 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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3.2.4. Sleep Mode
Software Sleep
Sleep Modes enable the XTend Modem to operate at minimal power consumption when not in
use. Three Sleep Mode options are available:
•Host Controlled (Pin Sleep)
•Wake on Serial Port activity (Serial Port Sleep)
•Wake on RF activity (Cyclic Sleep)
For the modem to transition into Sleep Mode, SM (Sleep Mode) Parameter must have a non-zero
value and one of the following must occur:
1. The modem is idle (no data transmission or reception) for a user-defined period of time [See
ST (Time before Sleep) Command]
[OR]
2. GPI2 pin is asserted [GPI2 is equivalent to DTR (Data-Terminal-Ready) under RS-232
operation. Refer to the RS-232 Operation [p7] section for more information.]
While in Sleep Mode, the modem will not transmit or receive data until the modem first shifts
back to Idle Mode. The return to Idle Mode is triggered by the de-assertion of GPI2 or the arrival
of a serial byte through the DI pin. Sleep Mode is enabled and disabled using SM Command.
Table3‐02. SummaryofSleepModeConfigurations
Sleep Mode
Setting Transition into
Sleep Mode Transition out of
Sleep Mode Related
Commands Power
Consumption
Pin Sleep
(SM=1)
Host can shut down and
wake modems. Assert GPI2
(SLEEP) pin.
Note: The module will
complete a transmission or
reception before activating
Pin Sleep.
De-Assert GPI2 (SLEEP)
pin. SM Typically 17 mA
Serial Port Sleep
(SM=2)
Automatic transition into
Sleep Mode after user-
defined period of inactivity
(no transmitting or
receiving). Period of
inactivity set using ST
Command.
When serial byte is received
on the DI pin. SM, ST Typically 45 mA
Cyclic Sleep
(SM=4-8)
Transitions into and out of Sleep Mode in cycles (user-
selectable wake-up interval of time set by SM Command).
The Cyclic Sleep interval time must be shorter than “Wake-
up Initializer Timer” (set by LH Command).
(Can be forced into Idle Mode using GPI2 (SLEEP) pin if
PW (Pin Wake-up) Command is issued.)
HT, LH, PW, SM, ST Typically 25 mA
(when sleeping, SM=4 ,
1 sec, @120K baud)
FormoreinformationaboutSleepModes,refertotheindividualcommandslistedin“RelatedCommands”
columnofthetable.SMCommandisthebeststartingpoint.
3.2.5. Shutdown
Hardware Sleep
Shutdown Mode offers the lowest power mode available to MaxStream modem users (< 1 µA).
This mode is not supported by the stand-alone XTend RF Modem, but is available through the
OEM RF Module that is mounted inside the stand-alone XTend RF Modem.
Contact MaxStream Technical Support for more information.
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3.2.6. Command Mode
To set or read modem parameters; the modem must first enter Command Mode (a state in which
incoming characters are interpreted as commands). Two command types are available:
•AT Commands
•Binary Commands
For modified parameter values to persist in the modem’s registry, changes must be saved to non-
volatile memory using WR (Write) Command. Otherwise, parameters are reset to previously
stored values after 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. [See “Default AT Command Mode Sequence” below.]
Use the “Terminal” tab (or other serial communications software) of the X-CTU Software to
enter the sequence.
[OR]
2. Force entrance into AT Command Mode by keeping the configuration switch [Figure 1-01a,
p6] pressed for two seconds.
Default AT Command Mode Sequence:
•No characters sent for one second [see BT (Guard Time Before) Command]
•Input three plus characters (“+++”) within one second [see CC (Command Sequence
Character) Command.]
•No characters sent for one second [see AT (Guard Time After) Command.]
To Send AT Commands to the RF Modem:
Figure3‐08. SyntaxforsendingXTendATCommands
NOTE: To read a current parameter value stored in a register, leave the parameter field blank.
The preceding example would change the modem Destination Address “1F”. To store the new
value to the modem’s non-volatile (long term) memory, use the WR (Write) Command.
The “Modem Configuration” tab of the X-CTU Software [p22] provides a software user interface
that facilitates the programming of RF modems. A more in depth look at modem programming is
in the Advanced Configuration section [p20].
To Exit 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 on that illustrates programming the modem using AT Commands, refer to the
‘Terminal tab’ section on p21.
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Binary Command Mode
Sending and receiving parameter values using binary commands is the fastest way to change the
operating parameters of the XTend RF Modem. Binary commands are used most often to sample
signal strength (DB parameter) and/or error counts; or change modem addresses and channels
for polling data systems. 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 data types 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 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 must be asserted in order to send binary commands to the RF 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 radio is continuously
receiving data, the radio will wait for a break in the received data before executing the command.
The signal will frame the response coming from the binary command request [Figure 3-09].
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, they are two bytes long with the least significant byte sent first.
Binary commands that return one parameter byte must be written with two parameter bytes.
Refer to p22 for a binary programming example.
Commands can be queried for their current value by sending the command logically ORed (bit-
wise) 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.
Figure3‐09. BinaryCommandWritethenRead
Signal#4isCMD
Signal#1istheDINsignaltothemodem
Signal#2istheDOUTsignalfromthemodem
Signal#3is
Inthisgraph,avaluewaswrittentoaregisterandthen
readouttoverifyit.Whilenotinthemiddleofother
receiveddata,notethatthesignaloutlinesthedata
responseoutofthemodem.
IMPORTANT: For the XTend Modem to recognize binary commands, the RT (GPI1 Configuration)
parameter must be set to one. If binary programming is not enabled (RT != 1), the
modem will not recognize the data as binary commands.
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4. ModemConfiguration
4.1. Automatic DIP Switch Configurations
Each time an RF Modem is powered on, AT commands are sent to the on-board RF 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.
Figure4‐01. DIPSwitches
Table4‐01. Power‐upOptions‐CommandssentasresultofDIPSwitchSettings(SW=DIPSwitch)
Switches Condition Behavior Commands Sent During Power-up
If SW1 & SW2
are ON (up) Restore Defaults ATRE (Restore Defaults)
ATWR (Write defaults to non-volatile memory)
If SW1 is ON (up) RS-232 Operation ATCS 0 (RS-232, CTS flow control)
Switches 1 & 2
(Restore Defaults /
Serial Interfacing) If SW1 is OFF (down) RS-485/422
Operation ATCS 3 (RS-485 or RS-422 Operation)
If SW5 is ON (up) &
SW6 is OFF (down) Peer-to-Peer ATAM (Auto-setMY, MY = unique)
ATDT FFFF (Destination Address)
ATMT 3 (Multi-Transmit option)
If SW5 & SW6 are
OFF (down) Multipoint Base ATMY 0 (Source Address)
ATDT FFFF (Destination Address)
ATMT 3 (Multi-Transmit option)
If SW5 is OFF (down) &
SW6 is ON (up) Multipoint Remote ATAM (Auto-set MY, MY = unique)
ATDT 0 (Destination Address)
ATMT 0 (Multi-Transmit option)
ATRR A (Retries)
Switches 5 & 6
(TX/RX Modes)
If SW5 is ON (up) &
SW6 is ON (up) User Defined Processor is disabled and AT Commands are not sent to
the modem (except for CS command as shown below.)
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 RF 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].
Table4‐02. UserDefinedMode(Switches5and6areON(up))
DIP Switches ON (up) Condition Command Sent During Power-up
If CS = 0, 1, 2 or 4 CS parameter remains the same
SW1, SW5 and SW6 If CS = 3 ATCS 0 (RS-232 operation, flow control)
SW2, SW5 and SW6 If CS = 2 ATCS 2 (GPO1 high)
SW5 and SW6 only If CS = 0, 1, 2, 3 or 4 ATCS 3 (RS-485/422 Operation)
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