XECOM XE900S-500 User Manual

XE900S-500 Smart Spread Spectrum Transceiver

XE900S-500

June 2005

Description

The XE900S-500 combines a spread spectrum
transceiver and micro-controller in a single, easy-to­use, FCC Part 15 Registered module. The embedded
communications controller manages the Frequency
Hopping Spread Spectrum (FHSS) link and the host
system interface.

The XE900S-500 supports two unique features to
simplify wireless networking. Count-Off™ allows the
network master to quickly retrieve the status of 125
remote nodes with a single broadcast command.
SensorOnAir

TM

eliminates the need for an application
controller by utilizing the communications controller to
directly manage analog inputs and digital control lines.

Xecom also offers a low power spread spectrum model,
the XE900SL10, for applications that require less range.
The XE900SL10 has an obstructed range of 300 feet but
is smaller, costs less and uses significantly less power .

Features

* Small Size: 1.295” by 1.410” by 0.255”
* Serial Control and Configuration of the W ireless Link.
* Supports a 254 node point-to-multipoint network
* Programmable Transmit Power Output 100 to 500 mW.

* T ypical Receiver Sensitivity -100 dBm
* Obstructed signal range to 1000 feet;
* W ireless Data Rate 76.8K bps, half-duplex
* Low power Consumption

XE900S-500: 1000 mA @ 3.3 V olts; when transmitting
at 500 mW output power; less than 1 mA of current
flows in Sleep Mode or Power-Down modes

* SensorOnAir

TM

(patent pending) allows direct

connection of sensors to the Smart Transceiver

* Count-OffTM (patent pending) allows the host node to

download the status of all nodes in under 10 seconds.
* Operating T emperature Range of -40 to +85 C
* FCC Part 15 Registered

XE900S-500 Block Diagram

Antenna

SAW

FILTER

MUX

AMP

TRANSCEIVER

SAW

FILTER

XECOM (1) XE900S-500

ROM

COMM.
CONTROLLER

Ser ia l I/ F

Analog
Inputs

Digital I/O

XE900S-500 MECHANICAL SPECIFICATIONS

F

Top View

A

E

H

G

B

I

C

D

H

Dimension Description Inches MM

A Module Width 1.295 32.89
B Module Length 1.410 35.81
C Module Thickness 0.255 6.48
D Minimum Lead Length 0.125 3.18

E Antenna Width 0.134 3.40

F Edge to Antenna 0.995 25.27
G Pin to Pin Spacing 0.100 2.54
H Edge to End of Pin Row 0.155 3.94

I Pin Row Length 1.100 27.94

XECOM (2) XE900S-500

Layout PCB for XE900S-500 and XE900SL10

Despite the fact that the XE900S-500 is substantially
larger module than the XE900SL10, a common PCB
layout can be used to support both products. This
makes it easy to accommodate applications which
include nodes with both long range and short range
requirements.

The XE900S-500 and XE900SL10 can share board layout
because of common pin assignments. Pins 1 through 8
of the XE900SL10 are equivalent to Pins 3 through 10 on
the XE900S-500; they have the same functions and are
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

Vcc

1

XE900S-500

2

The XE900SL10 requires a separate pin row for Pins 10
through 14. These pins will be hidden under the XE900S­500 module when the larger module is installed. The
XE900SL10 also includes one unique signal, Reset.
Reset is an active high signal that can be left
unconnected if no external reset is desired.

The figure below shows the overlapping layout that
supports both modules. The XE900S-500 outline and
pins are shown in green. XE900SL10 pins and outline are
shown in red.

/TXD

/RXD

/CTS

/RTS
DIO3
DIO2
DIO1
DIO0

ADC1/NC

ADC0

3/1
4/2
5/3
6/4
7/5
8/6
9/7
10/8
11/9
12

XE900SL10

14
13
12
11
10

Reset
ADC0
ADC1
Vcc
Gnd

XECOM (3) XE900S-500

Using the XE900S-500 Power Saving Modes

The XE900S-500 includes three low power operating
modes (Sleep, Power-Down and RF Monitor) to allow
the host application to make maximum use of the
available power. The #P command determines how the
transceiver will operate when not being asked to
transmit or receive an RF signal. Below are descriptions
of all of the XE900S-500 operating modes.

IDLE: In Idle Mode all circuits within the XE900S-500 are
powered and available for immediate action. This
includes the RF receiver which actively monitors the air
for an incoming communications request. Current draw
in Idle Mode is typically 23 milliamps.

SLEEP: In Sleep Mode all circuits within the XE900S-500
are powered-down to reduce consumption. The
XE900S-500 will not accept commands or respond to
incoming RF communications requests. Any input on
the TXD line will wake the transceiver and return it either
the Idle or Power-Down Mode which ever mode it was
last in before being put into Sleep Mode. Current draw in
Sleep Mode is less than 100 microamps.

RF Monitor Mode: The XE900S-500 includes 4 RF
monitor modes. In each of these RF Monitor modes the
transceiver sits in power down mode for a prescribed
period of time. The transceiver then wakes up, turns on
its receiver and checks for incoming messages. If no
messages are received the transceiver returns to power
down mode after about 200 milliseconds. If a carrier is
detected, the transceiver completes the transaction
before returning to power down mode. Intervals of 2
seconds (#P3, 4 seconds (#P4), 8 seconds (#P5) and 16
seconds (#P6) can be selected.

RF Receive Mode: In RF Receive Mode the XE900S-500
is actively receiving an incoming 900 MHz data signal.
Current draw in RF Receive Mode is typically 35
milliamps.

RF T ransmit Mode: In RF Transmit Mode the XE900-500
is actively transmitting a 900 MHz data signal. Current
draw in Transmit mode is no more than 1000 milliamps
with the transmit output power set to maximum, 500
milliwatts.

Power-Down: In Power-Down Mode all RF circuitry is
shut down but the communications controller remains
active to accept AT commands. In this mode the
XE900S-500 cannot respond to incoming RF
communications requests. If a transmit RF or Receive RF
command is received, the XE900S-500 can activate the
RF section in under 200 microseconds. Current draw in
Power-Down Mode is less than 800 microamps.

A T Command Control

The power saving modes are controlled by the AT#Pn

command, see below.
AT#P0 - Sets the transceiver to Idle mode.
AT#P1 - Sets the transceiver to Sleep Mode.
AT#P2 - Sets the transceiver for Power-Down Mode.
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

VCC 2
/TXD 3
/RXD 4

/CTS 5

/RTS 6
DIO3 7
DIO2 8
DIO1 9
DIO0 10

ADC1 11
ADC0 12

XE900S-500

T op View

SIGNAL PINS DESCRIPTION

Ground 1 Common voltage reference for the XE900S-500.
V C C 2 3.3 Volt power for the XE900S-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 1 0 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-bit Analog 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-bit Analog to Digital Convertor . ADC0 may also be configured as a digital
input if no analog inputs are required.

XECOM (5) XE900S-500