XE900S-500
June 2005
XE900S-500 Smart Spread Spectrum Transceiver
Description
Features
The XE900S-500 combines a spread spectrum
* SmallSize:1.295”by1.410”by0.255”
transceiver and micro-controller in a single, easy-to-
* Serial Control and Configuration of the Wireless Link.
use, FCC Part 15 Registered module. The embedded
* Supports a 254 node point-to-multipoint network
communications controller manages the Frequency
* ProgrammableTransmit Power Output 100 to 500 mW.
Hopping Spread Spectrum (FHSS) link and the host
* Typical Receiver Sensitivity -100 dBm
system interface.
* Obstructed signal range to 1000 feet;
The XE900S-500 supports two unique features to
* Wireless Data Rate 76.8K bps, half-duplex
simplify wireless networking. Count-Off™ allows the
* Low power Consumption
XE900S-500:1000mA @3.3Volts;whentransmitting
network master to quickly retrieve the status of 125
at 500 mW output power; less than 1 mA of current
remote nodes with a single broadcast command.
flows in Sleep Mode or Power-Down modes
SensorOnAir TM eliminates the need for an application
* SensorOnAir TM (patent pending) allows direct
controller by utilizing the communications controller to
connection of sensors to the Smart Transceiver
directly manage analog inputs and digital control lines.
* Count-Off TM (patent pending) allows the host node to
download the status of all nodes in under 10 seconds.
Xecom also offers a low power spread spectrum model,
* Operating Temperature Range of -40 to +85 C
the XE900SL10, for applications that require less range.
* FCC Part 15 Registered
The XE900SL10 has an obstructed range of 300 feet but
is smaller, costs less and uses significantly less power.
XE900S-500 Block Diagram
Antenna
SAW
ROM
FILTER
Serial I/F
MUX
TRANSCEIVER
COMM.
CONTROLLER
Analog
Inputs
Digital I/O
AMP
SAW
FILTER
XECOM
(1)
XE900S-500
XE900S-500 MECHANICAL SPECIFICATIONS
F
E
H
Top View
G
B
I
C
A
D
H
Dimension Description
Inches
MM
A
ModuleWidth
1.295
32.89
B
ModuleLength
1.410
35.81
C
ModuleThickness
0.255
6.48
D
MinimumLeadLength
0.125
3.18
E
AntennaWidth
0.134
3.40
F
EdgetoAntenna
0.995
25.27
G
PintoPinSpacing
0.100
2.54
H
Edge to End of Pin Row
0.155
3.94
I
PinRowLength
1.100
27.94
XECOM
(2)
XE900S-500
Layout PCB for XE900S-500 and XE900SL10
Despite the fact that the XE900S-500 is substantially
The XE900SL10 requires a separate pin row for Pins 10
larger module than the XE900SL10, a common PCB
through 14. These pins will be hidden under the XE900S-
layout can be used to support both products. This
500 module when the larger module is installed. The
makes it easy to accommodate applications which
XE900SL10 also includes one unique signal, Reset.
include nodes with both long range and short range
Reset is an active high signal that can be left
requirements.
unconnected if no external reset is desired.
The XE900S-500 and XE900SL10 can share board layout
The figure below shows the overlapping layout that
because of common pin assignments. Pins 1 through 8
supports both modules. The XE900S-500 outline and
of the XE900SL10 are equivalent to Pins 3 through 10 on
pins are shown in green. XE900SL10 pins and outline are
the XE900S-500; they have the same functions and are
shown in red.
placed in the same sequence. Pin 9 on the XE900SL10 is
an unused pin and therefore does not conflict with the
ADC1 signal assigned to Pin 11 of the XE900S-500.
XE900S-500/XE900SL10 Overlay
Gnd
1
XE900S-500
Vcc
2
/TXD
3/1
XE900SL10
/RXD
4/2
/CTS
5/3
/RTS
6/4
DIO3
7/5
14
Reset
DIO2
8/6
13
ADC0
DIO1
9/7
12
ADC1
DIO0
10/8
11
Vcc
ADC1/NC
11/9
10
Gnd
ADC0
12
XECOM
(3)
XE900S-500
Using the XE900S-500 Power Saving Modes
The XE900S-500 includes three low power operating
RF Monitor Mode : The XE900S-500 includes 4 RF
modes (Sleep, Power-Down and RF Monitor) to allow
monitor modes. In each of these RF Monitor modes the
the host application to make maximum use of the
transceiver sits in power down mode for a prescribed
available power. The #P command determines how the
period of time. The transceiver then wakes up, turns on
transceiver will operate when not being asked to
its receiver and checks for incoming messages. If no
transmit or receive an RF signal. Below are descriptions
messages are received the transceiver returns to power
of all of the XE900S-500 operating modes.
down mode after about 200 milliseconds. If a carrier is
detected, the transceiver completes the transaction
IDLE: In Idle Mode all circuits within the XE900S-500 are
before returning to power down mode. Intervals of 2
powered and available for immediate action. This
seconds (#P3, 4 seconds (#P4), 8 seconds (#P5) and 16
includes the RF receiver which actively monitors the air
seconds (#P6) can be selected.
for an incoming communications request. Current draw
in Idle Mode is typically 23 milliamps.
RFReceiveMode : In RF Receive Mode the XE900S-500
is actively receiving an incoming 900 MHz data signal.
SLEEP : In Sleep Mode all circuits within the XE900S-500
Current draw in RF Receive Mode is typically 35
are powered-down to reduce consumption.
The
milliamps.
XE900S-500 will not accept commands or respond to
incoming RF communications requests. Any input on
RF TransmitMode : InRFTransmitModetheXE900-500
the TXD line will wake the transceiver and return it either
is actively transmitting a 900 MHz data signal. Current
the Idle or Power-Down Mode which ever mode it was
draw in Transmit mode is no more than 1000 milliamps
last in before being put into Sleep Mode. Current draw in
with the transmit output power set to maximum, 500
Sleep Mode is less than 100 microamps.
milliwatts.
Power-Down: In Power-Down Mode all RF circuitry is
AT CommandControl
shut down but the communications controller remains
The power saving modes are controlled by the AT#Pn
active to accept AT commands.
In this mode the
command, see below.
XE900S-500 cannot respond to incoming RF
AT#P0 - Sets the transceiver to Idle mode.
communications requests. If a transmit RF or Receive RF
AT#P1 - Sets the transceiver to Sleep Mode.
command is received, the XE900S-500 can activate the
RF section in under 200 microseconds. Current draw in
AT#P2 - Sets the transceiver for Power-Down Mode.
Power-Down Mode is less than 800 microamps.
AT#P3 - RF Monitor Mode (2 second interval)
AT#P4 - RF Monitor Mode (4 second interval)
AT#P5 - RF Monitor Mode (8 second interval)
AT#P6 - RF Monitor Mode (16 second interval)
XECOM
(4)
XE900S-500
XE900S-500 PIN CONFIGURATION
GND
1
XE900S-500
VCC
2
TopView
/TXD
3
/RXD
4
/CTS
5
/RTS
6
DIO3
7
DIO2
8
DIO1
9
DIO0
10
ADC1
11
ADC0
12
SIGNAL PINS
DESCRIPTION
Ground
1
Common voltage reference for the XE900S-500.
VCC
2
3.3VoltpowerfortheXE900S-500.
/TXD
3
Transmit Data is the data input to the XE900S-500
/RXD
4
Received Data is the data output from the XE900S-500.
/CTS
5
Clear to Send provides hardware flow control from the XE900S-500. The XE900S-500
drives /CTS high to signal the host to temporarily stop the flow of data on the /TXD.
/RTS
6
Request to Send provides hardware flow control from the host system. The host system
drives /RTS high to signal the XE900S-500 to temporarily stop the flow of data on /RXD.
DIO3
7
DIO3 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the XE900S-500.
DIO2
8
DIO2 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the XE900S-500.
DIO1
9
DIO1 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the XE900S-500.
DIO0
10
DIO0 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the XE900S-500.
ADC1
11
Analog Input 1 to the XE900S-500 communications controller. ADC1 connects to an
internal 12-bitAnalog to Digital Convertor. ADC0 may also be configured as a digital
input if no analog inputs are required.
ADC0
12
Analog Input 0 to the XE900S-500 communications controller. ADC0 connects to an
internal 12-bitAnalog to Digital Convertor. ADC0 may also be configured as a digital
input if no analog inputs are required.
XECOM
(5)
XE900S-500
ABSOLUTE MAXIMUM RATINGS
VCC
3.9Volts
Storage Temperature
-55 O C to +125 O C
Operating Temperature Range
-40 O C to +85 O C
WARNING: Exceeding any of these ratings will void the warranty and may damage the device
XE900S-500 ELECTRICAL SPECIFICATIONS
Parameter
Min
Typ
Max
Units
Comments
VCC
2.7
3.3
3.6
Volts
Transceiver power
ICC
1000
mA
Transmit (500 mW output)
35
mA
Receive Mode
23
mA
Idle Mode
2.2
mA
Avg; 2-sec RF Monitor interval
1.1
mA
Avg; 4-sec RF Monitor interval
0.6
mA
Avg; 8-sec RF Monitor interval
0.3
mA
Avg; 16-sec RF Monitor interval
0.8
mA
Power-Down Mode
0.10
mA
Sleep Mode
Output Power:
100
500
mW
50 Ohm Load
Wireless Receive Sensitivity
-100
dBm
Range thru Physical Obstructions
1000
feet
500 mW output
Frequency Hopping Channels
50
Frequency Band
902
928
MHz
Antenna Output Impedance
50
Ohms
Voh
2.25
Volts
VCC=3.3Volts
Vol
0.75
Volts
VCC=3.3Volts
Vih
2.25
Volts
VCC=3.3Volts
Vil
0.75
Volts
VCC=3.3Volts
XECOM
(6)
XE900S-500
XE900S-500 TYPICAL CONNECTION DIAGRAM
3.3V
Antenna
C1 C2 C3
C4 C5
GND
L1
VCC
/TXD
Host
/RXD
Serial
I/F
/CTS
/RTS
DIO3
DIO2
DIO1
DIO0
ADC1
ADC0
Parts List for XE900S-500Typical Connection Diagram
Reference
Designation
Qty
Description
C1
1
Capacitor, Electrolytic, 100 ufd, 10Volts
C2,C4
2
Capacitor 0.1 ufd, 10Volts
C3,C5
2
Capacitor 47 pfd, 10Volts
L1
1
Coilcraft0603HC-7N5XJB
Antenna *
1
50 Ohm, 1/4 Wave;
* TheAntenna connector on XE900S-500 models is a Male MMCX
connector.An female MMCX to Female SMA adapter is needed for
the antenna connection
XECOM
(7)
XE900S-500
XE900S-500 COMMUNICATIONS CONTROLLER
The XE900S-500 uses an internal micro-controller to
Command Prefix - Each command, except the A/
control communications. This micro-controller manages
command, begins with the AT prefix. The "A" and "T"
the interface to the host system, determines when the
may be either both upper case or both lower case but
communications link is available, and formats data for
cannot be of different cases. The prefix identifies parity of
the RF communications.
the commands sent to the XE900S-500 by comparing the
parity bits of the "A" and the "T" characters.
HOST INTERFACE
TheXE900S-500hastwoprimaryinterfacestothesystem
Command Line - Commands may be strung together in a
host; the serial interface and the direct sensor interface
single command line of up to 30 characters. Commands in
supported by the SensorOnAir™ feature. Management
the command string are executed in the sequence they
of both interfaces is the responsibility of the
appear.
communications controller.
Omitted Parameters - Most commands include a
RS232 Interface
parameter which determines the function setting. When
The XE900S-500 supports a 4-signal serial interface. For
the command parameter is omitted from the command
mostapplicationstheXE900S-500willactasaDCE.Control
string, it is assumed to be a 0.
and configuration of the XE900S-500 takes place through
Result Codes - A result code is normally issued after each
the serial interface using modem-likeAT commands. The
action. Result codes may be provided as full words, one
serial data rate is configurable from 1200 bits per second
or two digit numeric codes, or may be disabled all
to 115.2K bits per second. The supported serial interface
together. Each result code ends with a carriage return
signals are listed below.
when numeric result codes are chosen. When full word
/TXD- Transmit Data; the input to the XE900S-500 for
result codes are chosen, a Line Feed and Carriage Return
AT commands and Data to be transmitted on the
precede and follow each result code.
wireless network.
Disconnect Sequence - A three character sequence
/RXD- Received Data; the output from the XE900S-500
initiates a disconnect of the wireless link. The sequence
for received RF data and responses to AT
“~~~” is assigned to disconnect the link.
commands.
DIRECTCONNECTIONOFSENSORS:
/RTS - Request to Send, provides the hardware flow
SensorOnAir ™
control input to the XE900S-500. The DTE
Sensors can be connected directly to the XE900S-500
removes RTS to stop the XE900S-500 from
without requiring an applications controller. In this
sending more data on the RXD line.
SensorOnAir™ configuration the XE900S-500
/CTS - Clear to Send, is the hardware flow control output
communications controller controls the operation of the
from the XE900S-500. The XE900S-500
sensors.
deactivates Clear to Send to advise then host to
Sensor I/O Lines
stop inputting data on the TXD lead.
SensorOnAir controls the operation of 6 I/O lines to the
XE900S-500AT CommandFormat
XE900S-500. This includes 2 analog inputs, ADC0 and
AT commands issued to the XE900S-500 follow a strict
ADC1,and4digitalI/Olines,DIO0,DIO1,DIO2,andDIO3.
format. Each command begins with the prefix AT and
ADC0andADC1areconnectedtoa12-bitanalogtodigital
ends with a carriage return. The XE900S-500
converter and use a 2.5 volt reference derived from VCC
communications controller accepts commands at data
as their reference voltage. The digital I/O lines can be
rates from 1200 to 115,200 bps. The default serial data
programmed to act as either inputs or outputs.
rate is 9600 bps and can be changed using register S23.
The communications controller uses the AT command
prefix to automatically determine the parity of the
incoming characters.
XECOM
(8)
XE900S-500
XE900S-500 COMMUNICATIONS CONTROLLER
Configuring the XE900S-500 for Sensor Operation
WIRELESSCOMMUNICATIONS
All SensorOnAir control functions for the analog inputs
The communications controller manges the RF Link. This
and digital I/O’s are performed by the communications
includes the frequency hopping algorithm for spread
controller within the XE900S-500. Modem-like AT
spectrum operation; collision avoidance, node
commands loaded through the serial interface, program
addressing, and packetizing data. The communications
the functions of the analog and digital I/O lines. The AT
controller allows support for point-to-point, point-to-
commands used to program the SensorOnAir functions
multipoint or multipoint networks.
are then stored in the XE900S-500 Flash memory. This
allows the XE900S-500 to be first programmed and then
Carrier Sense MultipleAccess (CSMA)
installed in the application. The communications
To prevent collisions between network nodes the
controller uses the information stored in Flash memory to
XE900S-500usesaCarrierSenseMultipleAccessprotocol
control the analog and digital I/O lines.
for each network transceiver. In normal communications
all nodes, including the Master node in a point-to-
SensorOnAirCommands ™
Multipoint network, listen for communications activity
Below is a list of the AT commands used to program the
before initiating a session. If a wireless link already exists,
direct control of sensors using the communications
the transceiver waits until that session is complete before
controllerintheXE900S-500.
initiating a wireless link.
S107 - Defines the function of the programmable I/O lines.
DataPackets
The two analog input lines, ADC0 and ADC1, can
All data presented by the system host is placed into
also be defined as digital I/O lines if needed. The four
packets by the XE900S-500 communications controller
programmable digital I/O lines, DIO0, DIO1, DIO2,
for transmission across the wireless link. These packets
and DIO3; can be set as either inputs or outputs. The
provide addressing and error correction for the wireless
valueofthiscommandisstoredinflashmemorywithin
communications. The communications controllers place
the XE900S-500.
the data in packets only for the wireless link. The data is
AT&IAn? - This command allows a local host to read the value
extracted from the packets before being sent out the serial
of Analog Input “n.”
interface.
AT&IDn? - This command allows a local host to read the
FileTransfer Mode
status of Digital I/O “n.”
Xecom’s XE900S-500 incorporates a File Transfer mode
that uses a simplified networking protocol so that the
AT&IDn=z - This command allows a local host equipment to
maximum data transfer rate is achieved. In this mode the
set the condition of the local digital output “n.” When
z=0 the output is set to a logic low; when z=1 the
XE900S-500 does not automatically retransmit blocks
output is set to a logic high.
containing errors. A CRC 16 checksum is calculated,
transferred at the end of the file, and checked by the
AT#IxxxAn? - This command allows the value ofAnalog Input
receiving unit. An “ERROR” message is displayed if the
“n” on node address “xxx” to be read remotely.
checksum calculated at the receive end does not match
AT#IxxxDn? - This command allows the status of Digital I/O
the checksum transmitted with the data.
“n” on node address “xxx” to be read remotely
The File Transfer Mode is controlled by the AT#T
AT#IxxxDn=z - This command allows the condition of the
command. The format of the command isAT#Txx; where
local digital output “n” on node address “xxx” to be
xx is the destination address of the file. Following is a
set remotely. When z=0 the output is set to a logic
sample file transfer.
low; when z=1 the output is set to a logic high.
XECOM
(9)
XE900S-500
XE900S-500 COMMUNICATIONS CONTROLLER
Sample FileTransfer
Transmitter