MaxStream 9XTEND Users Manual

XTend™ OEM RF Module

Product Manual v1.0

For MaxStream OEM RF Module part numbers that begin with: XT09-R…, XT09-M…

1 Watt Transmit Power, 256-bit AES Encryption

XTend OEM RF Module

RF Operation

Advanced Programming

Appendices

355 South 520 West, Suite 180
Lindon, UT 84042
Phone: [phone]
Fax: [phone]

[e-mail]
www.maxstream.net

M100115

11.10.2004

XTend™ OEM RF Module – Product Manual v1.0

© 2004 MaxStream, Inc. All rights reserved

No part of the contents of this manual may be transmitted or
reproduced in any form or by any means without the written
permission of MaxStream, Inc.

XTend™ is a trademark of MaxStream, Inc.

Phone: [phone]

Live Chat: www.maxstream.net

E-Mail: [e-mail]

© 2004 MaxStream, Inc. Confidential & Proprietary ii

XTend™ OEM RF Module – Product Manual v1.0

Contents

XTend™ OEM RF Module 4

Features 4 FCC Certification 42

Worldwide Acceptance 4 Labeling Requirements 42

Specifications 5
Pin Signals 6
Electrical Characteristics 7

Timing Specifications 7

Mechanical Drawings 8

RF Operation 9

Serial Communications 9

UART-Interfaced Data Flow 9
Serial Data 9
Flow Control 10

Modes of Operation 11

Idle Mode 11
Transmit Mode 11
Receive Mode 13
Shutdown Mode 13
Sleep Mode 14
Command Mode 15

RF Communication Options 17

Addressing Options 17
Streaming Mode 18
Acknowledged Mode 19
Multi-Transmit Mode 21

Advanced Programming 22

Programming the Module 22

AT Command Example 22
Binary Command Example 22

Command Descriptions (short) 23

Command Descriptions (long) 24

Appendix A: Agency Certifications 42

FCC Notices 43
FCC-Approved Antennas (900 MHz) 44

IC (Industry Canada) Certification 46

Appendix B: Development Guide 47

XTend Development Kit Contents 47
Interfacing Hardware 47

MaxStream XTIB-R RS-232/485 Interface Board 48
Adapters 50
Antennas 51

Interfacing Protocols 52

RS-232 Operation 52
RS-485 (2-wire) Operation 54
RS-485 (4-wire) & RS-422 Operation 55

X-CTU Software 57

Appendix C: Additional Information 58

1-Year Warranty 58
Ordering Information 58
Contact MaxStream 59

© 2004 MaxStream, Inc. Confidential & Proprietary iii

XTend™ OEM RF Module – Product Manual v1.0

XTend™ OEM RF Module

The XTend OEM RF Module is MaxStream’s longest range drop-in
wireless solution. The module transfers a standard asynchronous serial
data stream between two or more modules and sustains RF data rates
up to 120,000 bps.

Features

Long Range

1 Watt Power Output (1 mW – 1 W, variable)

Range (@ 9600 baud):

• 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 baud):

• 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

10 hopping channels, each with over 65,000
network addresses available

FHSS (Frequency Hopping Spread Spectrum)

256-bit AES Encryption
(Refer to KY Command [p30])

Easy-to-Use

2.8 to 5.5 V power supply

Continuous RF data stream
up to 115.2 kbps

No configuration required

Advanced configurations available
through standard AT Commands

Transparent Operation
(Wireless links replace serial wires)

Portable
(small form-factor easily designed into a
wide range of data radio systems)

Software-selectable I/O interfacing rates

MODBUS,
I/O Support

Support for multiple data formats
(parity, start and stop bits, etc.)

XII™ Interference Immunity

Power-saving Shutdown & Sleep Modes

Free & Unlimited Technical Support

, , , (& more)

Worldwide Acceptance

FCC Pending (USA) [Refer to Appendix A for FCC Requirements]

Systems that contain XTend Modules inherit MaxStream’s FCC Certification

IC (Industry Canada) Pending

ISM (Industrial, Scientific & Medical) license-free 902-928 MHz frequency band

Manufactured under ISO 9001:2000 registered standards

© 2004 MaxStream, Inc. Confidential & Proprietary 4

XTend™ OEM RF Module – Product Manual v1.0

Specifications

Table 1.1. XTend OEM RF Module

XTend 900 MHz OEM RF Module Specifications

Performance @ 10,000 bps RF Data Rate @ 120,000 bps RF Data Rate

Transmit Power Output
(software selectable using PL Command)

Indoor/Urban Range Up to 3000’ (900 m) Up to 1500’ (450 m)

Outdoor
RF line-of-sight Range

I/O Serial Data Rate (Baud) 1200 – 230400 bps (Software selectable) 1200 – 230400 bps (Software selectable)

Sustained Throughput 115,200 bps 115,200 bps

RF Data Rate
(software selectable using BR Command)

Receiver Sensitivity -110 dBm -100 dBm

Receive Current 80 mA (@ 10000 bps) 80 mA (@ 120000 bps)

Shutdown Mode Power Down < 1 µA < 1 µA

Pin Sleep Power Down 147 µA 147 µA

16 sec cyclic sleep (SM=8) 0.8 mA 0.3 mA

Idle
Currents

8 sec cyclic sleep (SM=7) 1.4 mA 0.4 mA

4 sec cyclic sleep (SM=6) 2.6 mA 0.6 mA

2 sec cyclic sleep (SM=5) 4.8 mA 0.9 mA

1 sec cyclic sleep (SM=4) 8.7 mA 1.6 mA

General

Frequency 902-928 MHz

Spread Spectrum FHSS (Frequency Hopping Spread Spectrum)

Modulation FSK (Frequency Shift Keying)

Supported Network Topologies Peer-to-Peer (“Master/Slave” relationship not required), Point-to-Point, Point-to-Multipoint & Multidrop

Channel Capacity 10 hop sequences share 50 frequencies

Encryption 256-bit AES Encryption – Refer to the KY Command [p30] to implement

Physical Properties

Module Board Size 1.44” x 2.38” x 0.20” (3.65 cm x 6.03 cm x 0.50 cm)

Weight 0.64 oz (18 g)

Connector 20-pin

Operating Temperature -40 to 85º C (industrial)

Antenna

Connector Options RPSMA (Reverse-polarity SMA) or MMCX

Impedance 50 ohms unbalanced

Certifications (visit www.maxstream.net or call [phone] for complete list government agency approvals)

FCC Part 15.247 Pending

Industry Canada (IC) Pending

Table 1.2. XTend OEM RF Module Specifications – Relative to user-selected TX Power Output

Power Requirements (Supply voltage and TX currents relative to each TX Power Output option)

Transmit Power Output 1 mW 10 mW 100 mW 500 mW ** 1 W **

Supply Voltage 2.8 – 5.5 VDC 3.0 – 5.5 VDC 4.75 – 5.5 VDC

Transmit Current (5 V) typical 110 mA 140 mA 270 mA 500 mA 730 mA

Transmit Current (3.3 V) typical 90 mA 110 mA 260 mA 600 mA *

* 1W Power Output is not supported when using a 3.3 supply voltage.

** If the supply voltage for a given power setting is lower than the minimum supply voltage requirement (as shown in Table 1.2),
the TX Power Output will decrease to the highest power level setting given the current supply voltage.

1 mW - 1 W (software selectable) 1 mW - 1 W (software selectable)

Up to 14 miles (22 km) w/ dipole antenna
Up to 40 miles (64 km) w/ high-gain antenna

10,000 bps 120,000 bps

Up to 7 miles (11 km) w/ dipole antenna
Up to 20 miles (32 km) w/ high-gain antenna

© 2004 MaxStream, Inc. Confidential & Proprietary 5

XTend™ OEM RF Module – Product Manual v1.0

Pin Signals

Figure 1.1. XTend OEM RF Module Pin Numbers

Table 1.3. Pin Signal Descriptions

Pin

Number

1 GND - - yes Ground

2 VCC I - yes Power: 2.8 – 5.5 VDC

3

4 _PWR O yes -

5 DI I yes yes

6 DO O yes -

7 I no yes

8 GPI2 / SLEEP I yes -

9

RS-485 TX EN

10

11

12-20 reserved / do not connect

* Module has 10K Ω internal pull-up resistor

** Module has 10K Ω internal pull-down resistor

*** Module has 100K Ω internal pull-up resistor

(Low-asserted signals distinguished with a horizontal line over signal name.)

Mnemonic I/O

GPO2 /

RX LED

GPO1 /

/

GPI1 / /

CMD

High Impedance

during Shutdown

O yes -

O yes -

I yes -

I* no -

/

RSSI

O* no -

Must

Connect

Function

General Purpose Output 2: <Default (CD=2)> Pin is driven low. Refer to the
CD Command [p26] for other configuration options.

RX LED: Pin is driven high during RF data reception; otherwise, the pin is
driven low. Refer to the CD Command [p26] to enable.

Transmit_Power: Pin pulses low during RF transmission; otherwise, the pin
is driven high to indicate power is on and the module is not in Sleep or
Shutdown Mode.

Data In: Serial data entering the module (from the UART host). Refer to the
Serial Communications [p9] section for more information.

Data Out: Serial Data exiting the module (to the UART host). Refer to the
Serial Communications [p9] section for more information.

Shutdown: Pin is driven high during operation and low during Shutdown.
Shutdown enables the lowest power mode (< 1 µA) available to the module.
Refer to the Shutdown Mode [p13] section for more information.

General Purpose Input 2: reserved for future use

SLEEP: By default, SLEEP is not used. To configure this pin to enable Sleep

Modes, refer to the Sleep Mode [p14], SM Command [p37] & PW Command
[p33] sections.

General Purpose Output 1: reserved for future use

(Clear-to-Send): <Default (CS=0)> When pin is driven low, the UART
host is permitted to send serial data to the module. Refer to the Serial
Communications [p9] & CS Command [p27] sections for more information.

RS-485 Transmit Enable: To configure this pin to enable RS-485 half and
full duplex communications. Refer to the Serial Communications [p9] & CS
Command [p27] sections.

General Purpose Input 1: reserved for future use

(Request-to-Send): By default, is not used. To configure this pin to
regulate the flow of serial data exiting the module, refer to the Serial
Communications [p9] & RT Command [p36] sections.

CMD (Command): By default, CMD is not used. To configure this pin to
enable binary command programming, refer to the Binary Commands [p16]
& RT Command [p36] sections.

Configuration: Pin can be used as a backup method for entering Command
Mode during power-up. Refer to the Command Mode [p15] section for more
information.

Receive Signal Strength Indicator: By default, pin is used as an RSSI
PWM output after at the conclusion of the power-up sequence. Refer to the
RP Command [p35] for more information.

Note: When integrating the XTend Module with a Host PC Board, all lines that are not used should be left disconnected (floating).

© 2004 MaxStream, Inc. Confidential & Proprietary 6

XTend™ OEM RF Module – Product Manual v1.0

Electrical Characteristics

Figure 1.2. System Block Diagram

Basic wireless link between hosts

Table 1.4. AC Characteristics (Symbols correspond with Figure 1.2 and Figure 1.3, ATSY Parameter = 0)

Symbol Description Sleep Mode 115200 Baud Rate 9600 Baud Rate

The data flow sequence is initiated when the first byte of data is received in the DI Buffer of the
transmitting module (XTend Module A). As long as XTend Module A is not already receiving RF
data, data in the DI Buffer is packetized then transmitted over-the-air to XTend Module B.

Timing Specifications

Figure 1.3. Timing Specifications (“A” and “B” refer to Figure 1.2)

SM = 0

(No sleep)

9.4 msec 94 msec

SM = 8 16 sec 16 sec

SM = 7 8 sec 8 sec

SM = 6 4 sec 4 sec

TTX

Latency from the time data is

transmitted until it is received.

SM = 5 2 sec 2 sec

SM = 4 1 sec 1 sec

T

T

TTL

TRL

CLDL

CHDH

Time that _PWR pin (pin 4) is

driven low

Time that RX LED (pin 3)

is driven high

Time starting when goes low

until the first bit appears on D

OUT

Time after last bit of data until

goes high

-- 2.45 msec 29.6 msec

-- 2.26 msec 27.2 msec

-- 44 µsec 75 µsec

-- 7 µsec 7 µsec

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XTend™ OEM RF Module – Product Manual v1.0

Table 1.5. DC Characteristics (Vcc = 2.8 – 5.5 VDC)

Symbol Parameter Condition

VOL Output Low Voltage VOL = 0.33V (IO = 6 mA)

VOH Output High Voltage VOH = V

Figure 1.4. Input Thresholds vs. Supply Voltage

Mechanical Drawings

Figure 1.5. XTend Module Mechanical Drawings (with RPSMA antenna connector)

Figure 1.6. XTend Module Mechanical Drawings (with MMCX antenna connector)

- 0.7V (-IO = 6 mA)

SUPPLY

Input thresholds vs. supply voltage

2.5

2

1.5

1

I/O Voltage

0.5

0

2.5 3.5 4.5 5.5

Vcc

V(IL)
V(IH)

© 2004 MaxStream, Inc. Confidential & Proprietary 8

XTend™ OEM RF Module – Product Manual v1.0

RF Operation

WARNING: When operating at 1 Watt power output, observe a minimum separation distance of 2’ (0.6 m) between

modules. Transmitting in close proximity of other modules can damage module front ends.

Serial Communications

The XTend OEM RF Module interfaces to a host device through a TTL-level asynchronous serial
port. Through its serial port, the module can communicate with any UART voltage compatible
device or through a level translator to any RS-232/485/422 device.

UART-Interfaced Data Flow

Devices that have a UART interface can connect directly through the pins of the XTend Module as
is shown in the figure below.

Figure 2.1. System Data Flow Diagram in a UART-interfaced environment

(Low-asserted signals distinguished with horizontal line over signal name.)

Serial Data

Data enters the XTend Module through the DI pin (pin 5) as an asynchronous serial signal. The
signal should idle high when no data is being transmitted.

The UART performs tasks, such as timing and parity checking, that are needed for
communications. Serial communication consists of two UARTs configured with compatible
parameters (baud rate, parity, start bits, stop bits, data bits) to have successful communication.
Each data packet consists of a start bit (low), 8 data bits (least significant bit first) and a stop bit
(high). The following figure illustrates the serial bit pattern of data passing through the module.

Figure 2.2. UART data packet 0x1F (decimal number “31”) as transmitted through the XTend Module

Example Data Format is 8-N-1 (bits – parity - # of stop bits)

© 2004 MaxStream, Inc. Confidential & Proprietary 9

XTend™ OEM RF Module – Product Manual v1.0

Flow Control

Figure 2.3. Internal Data Flow Diagram (The five most commonly-used pin signals shown.)

DI (Data In) Buffer and Flow Control

When serial data enters the XTend Module through the DI Pin (pin 5), 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 [p11] for
more information), the module attempts to initialize an RF connection. If the module is already
receiving RF data, the serial data is stored in the module’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 Module).

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 module, the module
will receive data from the host faster than it can transmit the data over-the-air.

2. If the module is receiving a continuous stream of RF data or if the module is monitoring data
on a network, any serial data that arrives on the DI pin (pin 5) is placed in the DI Buffer. The
data in the DI buffer will be transmitted over-the-air when the module no longer detects RF
data in the network.

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).

Hardware Flow Control ( ). When the DI buffer is 17 bytes away from being full; by
default, the module de-asserts (high)
to FT (Flow Control Threshold, p29) and CS (GPO1 Configuration, p27) Commands.].
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 [p28]. 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 module, the module will
receive data from the transmitting module faster than it can send the data to the host.

2. If the host does not allow the module 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, p36), data
will not be sent out the DO Buffer as long as

Software Flow Control (XOFF). XON/XOFF software flow control can be enabled using the FL
(Software Flow Control) Command [p28]. This option only works with ASCII data.

to signal to the host device to stop sending data [refer

is re-

(pin 10) is de-asserted.

© 2004 MaxStream, Inc. Confidential & Proprietary 10

XTend™ OEM RF Module – Product Manual v1.0

Modes of Operation

XTend OEM RF Modules operate in six modes.

Figure 2.4. XTend Modes of Operation

Module can only be in one mode at a time.

Idle Mode

When not receiving or transmitting data, the module is in Idle Mode. The module uses the same
amount of power in Idle Mode as it does in Receive Mode.

The module 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)

• Shutdown condition is met (Shutdown Mode)

The module automatically transitions back to Idle Mode after responding to these conditions.

Transmit Mode

When the first byte of serial data is received from the UART in the DI buffer, the module attempts
to shift to Transmit Mode and initiate an RF connection with other modules. After transmission is
complete, the module 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
[RB (Packetization Threshold) Command, p33].

2. At least one character has been received by the UART and is pending for RF transmission;
and RO character times of silence been observed on the UART [RO (Packetization Timeout)
Command, p34].

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 (Max RF Packet Size,
p32), inclusive. Note that transition to Transmit Mode cannot take place during RF reception; the
RF reception must complete before the radio can transition into Transmit Mode.

If RB or RO conditions are met, the module 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
Command), converted to RF data and is transmitted over-the-air until the DI buffer is empty.

Channel initialization is the process of sending an RF initializer that synchronizes receiving
modules with the transmitting module. 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 module 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

© 2004 MaxStream, Inc. Confidential & Proprietary 11

XTend™ OEM RF Module – Product Manual v1.0

from the UART after the transmission began. If more data is pending, the transmitting module
assembles a subsequent packet for transmission.

Refer to the RF Communication Options [p17] section for information and state diagrams that
illustrate channel initialization and the sequence of events that follow. The XTend Module
supports the following RF Communication Options:

• Streaming Mode

• Acknowledged Mode

• Multi-Transmit Mode

RF Packet

Figure 2.5. 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 modules of information such as the hopping pattern
used by the transmitting module. 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 module. For example, a wake-up initializer is a type of RF
initializer used to wake remote modules 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 modules are in cyclic sleep.

Header

The header contains network addressing information that filters incoming RF data. The receiving
module checks for matching a VID, Hopping Channel and Destination Address. Data that does not
pass through all three network filter layers is discarded.

Figure 2.6. Network Layers Contained in the Header

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 module computes the CRC on all incoming RF data. Received data
that has an invalid CRC is discarded [See Receive Mode section, next page].

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XTend™ OEM RF Module – Product Manual v1.0

Receive Mode

If a module detects RF data while operating in Idle Mode, the module transitions into Receive
Mode to start receiving RF packets. Once a packet is received, the module 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 2.7. Receive Mode Data Flow

* Refer to the Addressing Options [p17] section of
the RF Communication Options section for more
information about address recognition.

The module 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 module is in Receive Mode, the serial data will be transmitted
after the module is finished receiving data and returns to Idle Mode.

Shutdown Mode

Hardware Sleep

For applications where power consumption must be kept to a minimum during idle periods,
Shutdown Mode offers the lowest power mode available to the module.

When the
communication in progress (transmit or receive) will be halted and any buffered data will be lost.
For any other mode of operation,
the module’s VCC pin draws less than 1 µA.

Immediately after the
there is a delay that must be observed. See reset section for the delay time.

While
TX_PWR, RX LED, DO and
RSSI indication) is driven low during shutdown.

The following input pins may continue to be driven by external circuitry when in shutdown mode:
PIN_PWR_DWN,

Note: Because the DO pin also goes high impedance, if the XTend Module is connected to a
processor, the UART receive pin could be floating. A weak pull-up should be placed between the
module and the microcontroller so that data isn’t interpreted as being transmitted to the
microprocessor.

pin (pin 7) is driven low, the module is forced into shutdown mode. Any

must be driven or pulled high. While in shutdown mode,

pin changes state from low to high, the module resets. After reset,

pin is driven low, the following pins are set to high impedance by the module: DCD,

(See pin signal descriptions, p6). The line (also used for

, DI and .

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XTend™ OEM RF Module – Product Manual v1.0

Sleep Mode

Software Sleep

Sleep Modes enable the XTend Module to operate at minimal power consumption when not in
use. Three Sleep Mode options are available:

• Pin Sleep (Host Controlled)

• Serial Port Sleep (Wake on Serial Port activity)

• Cyclic Sleep (Wake on RF activity)

For the module to transition into Sleep Mode, the module must have a non-zero SM (Sleep Mode)
Parameter and one of the following must occur:

1. The module is idle (no data transmission or reception) for a user-defined period of time [See
ST (Time before Sleep) Command, p39].

2. SLEEP pin (pin 8) is asserted (only for Pin Sleep option).

In Sleep Mode, the module will not transmit or receive data until the module 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 2.1. Summary of Sleep Mode Configurations

Sleep Mode
Setting

Pin Sleep
(SM = 1)

Serial Port Sleep
(SM = 2)

Cyclic Sleep
(SM = 4-8)

For more information about Sleep Modes, refer to the individual commands listed in “Related Commands”
column of the table. SM Command is the best starting point for implementing Sleep Mode configurations.

Transition into
Sleep Mode

A microcontroller can shut down and
wake modules by asserting (high)
SLEEP pin (pin 8).

Note: The module will complete a
transmission or reception even if Pin
Sleep is activated.

Automatic transition to Sleep Mode
occurs after a user-defined period of
inactivity (no transmitting or receiving of
data). The period of activity is defined
using the ST (Time before Sleep)
Command.

Automatic transition to Sleep Mode
occurs in cycles as defined by the SM
(Sleep Mode) Command.

Note: The cyclic sleep time interval must
be shorter than the “Wake-up Initializer
Timer” (set by LH Command).

Transition out of
Sleep Mode

De-assert (low)
SLEEP pin (pin 8).

When serial byte is
received on the DI pin
(pin 5).

After the cyclic sleep time
interval elapses.

Note: Module can be
forced into Idle Mode if
PW (Pin Wake-up)
Command is issued.

Related
Commands

Typical Power
Consumption

SM 147 µA

SM, ST 10 mA

1.6 mA
HT, LH, PW,
SM, ST

(when sleeping,
SM=4, 1 sec,
@120,000 baud)

Refer to the Hardware Sleep entry of the Shutdown Mode section [previous page] to enable the
module’s lowest power-consuming state (1 µA power down current).

© 2004 MaxStream, Inc. Confidential & Proprietary 14

XTend™ OEM RF Module – Product Manual v1.0

Command Mode

To set or read module parameters, the module must first enter “Command Mode” (state in which
incoming characters are interpreted as commands). Two command types are available for use:

• AT Commands

• Binary Commands

For modified parameter values to persist in the module registry, changes must be saved to non­volatile memory using WR (Write) Command. Otherwise, parameters are restored to previously
saved values when the module is powered off and then on again.

AT Commands

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.] 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 pin and turn the power going to the module off and back on (or
pulse the pin).

[If the module is mounted to a MaxStream XTIB-R Interface Board, press the configuration

switch down for 2 seconds.]

Default AT Command Mode Sequence (for transition to Command Mode):

• 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:

Send AT commands and parameters using the syntax shown below:

Figure 2.8. Syntax for sending AT Commands

NOTE: To read a parameter value stored in a register, leave the parameter field blank.

The preceding example would change the module Destination Address to “1F”. To store the new
value to non-volatile (long term) memory, subsequently send the Write (ATWR) Command before
powering off the module.

System Response. When a command is sent to the module, the module will parse and execute
the command. Upon successful execution of a command, the module returns an “OK” message. If
execution of a command results in an error, the module returns an “ERROR” message.

To Exit AT Command Mode:

1. Send ATCN (Exit Command Mode) Command.

[OR]

2. If no valid AT Commands are received within the time specified by CT (Command Mode
Timeout) Command, the Module automatically returns to Idle Mode.

For an example that illustrates programming the module using AT Commands, refer to the
“Advanced Programming” chapter [p22].

© 2004 MaxStream, Inc. Confidential & Proprietary 15

XTend™ OEM RF Module – Product Manual v1.0

Binary Commands

Sending and receiving register values using binary commands is the fastest way to change the
operating parameters of the module. Binary commands are used most often to sample the signal
strength (RS register) and/or error counts or change module address and channels for polling
systems when a quick response is necessary. Since the sending and receiving register values
takes place through the same serial data path as 'live' data (received RF payload), interference
between the two can be a concern.

Common questions about using binary command mode:

• What are the implications of asserting CMD in any of the various states while live data is
being sent or received?

• Specifically, is there a minimum time delay after serial data is sent before which we can
assert CMD and send a command?

• Is a delay required after CMD is de-asserted before we can send normal data?

• How can we know if data being received is the response from a command or live data?

Answers: The CMD line can be asserted to send a command to the radio anytime during
transmission or reception of data. Note that 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. 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 (see graphic below).

The CMD pin (pin 10) must be asserted in order to send binary commands to an XTend Module.
CMD can be asserted to recognize commands anytime during transmission or reception of data. A
minimum time delay of 100 µs (after the stop bit of the command byte has been sent) must be
observed before pin 10 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 module aborts the command and returns to Idle Mode. Note: When parameters are
sent, they are always two bytes long with the least significant byte sent first.

Commands can be queried for their current value by sending the command logically ORed 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 2.9. Binary Command Write then Read

Signal #4 is CMD (pin 10)

Signal #1 is the DIN (pin 5) signal
to the radio

Signal #2 is the DOUT (pin 6) signal
from the radio

Signal #3 is

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 signal outlines the data response out of the module.

(pin 9)

IMPORTANT: For the XTend Module to recognize a binary command, RT (GPI1 Configuration)

Command must be issued. If binary programming is not enabled (RT ≠ 1), the
module will not recognize that the CMD pin (Pin 10) is asserted and therefore will
not recognize the data as binary commands.

© 2004 MaxStream, Inc. Confidential & Proprietary 16

XTend™ OEM RF Module – Product Manual v1.0

RF Communication Options

The XTend OEM RF Module can be configured to operate in any of three RF communication
modes: Streaming, Acknowledged and Multi-Transmit. The mode is defined by parameters stored
in the transmitting module [see table below]. Receiving modules automatically adapt to the
correct mode on a per-packet basis, based on the contents of each received packet.

Table 2.2. Mode in Relation to Transmitting Module Parameter Values

RF Communication Mode RR Parameter Value MT Parameter Value

Streaming 0 0

Acknowledged >= 1 0

Multi-transmit Ignored >= 1

Addressing Options

In all the RF communication modes, transmission may be addressed to a specific module or
group of modules using the DT (Destination Address) and MK (Address Mask) commands. A
receiving module will only accept a packet if it determines the packet is addressed to it, either as
a global or local packet. The receiving module makes this determination by inspecting the
destination address of the packet and comparing it to its own address and address mask [Figure

2.10]

Figure 2.10. Address Recognition (@ the Receiving Module)

The transmitting module 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) [Figure 2.11]. It is assumed that the address masks on the
transmitting module and receiving module have been programmed to the same value for proper
operation in each RF Communication Mode.

Figure 2.11. Address Recognition (@ the Transmitting Module)

© 2004 MaxStream, Inc. Confidential & Proprietary 17

XTend™ OEM RF Module – Product Manual v1.0

Streaming Mode

Attributes: Highest data throughput

Lowest latency and jitter

Reduced immunity to interference

Required Parameter Values (TX Module): RR (Retries) = 0

Related Commands: Networking (DT, MK, MY), Serial Interfacing (PK, RB, RO, TT)

Recommended Use: Mode is most appropriate for data that is more sensitive to latency and/or

jitter than it is to occasional packet loss. For example: streaming audio or video.

Streaming Mode Connection Sequence

Events through the
“Transmit Packet” process
are common to all RF
communication options.
Refer to the Transmit Mode
section [p11] for more
information.

When streaming data,
RB and RO parameters
are used only on the
first packet. After
transmission begins,
the TX event will
continue uninterrupted
until the DI buffer is
empty or the streaming
limit (TT Command) is
reached. As with the
first packet, the p
of each subseque
packet includes up t
the maximum pack
size (PK Command).

The streaming lim
specified by the
transmitting mod
the maximum number of bytes the transmitting module can send in one transmission event. If
the TT parameter is reached, the transmitting module 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 receiving modules stay synchronized
with the transmitting module for the duration of the transmission event (from preceding packet
information). However, due to interference, some receiving modules may lose data (and
synchronization to the transmitting module), particularly during long transmission events.

Once the transmitting module has sent all pending data or has reached the TT limit, the
transmission event ends. The transmitting module will not transmit again for exactly RN delay
slots if the local (i.e. transmitting module’s) RN parameter is set to a non-zero value. The
receiving module(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 transmitting module,
during which several receiving modules may have become ready to transmit.

Streaming mode transmissions never acknowledged by receiving module(s)

Figure 2.12. Streaming Mode State Diagram

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© 2004 MaxStream, Inc. Confidential & Proprietary 18