ETC SSST900

SSST900-500
June 2005
SSST900-500 Smart Spread Spectrum Transceiver
Description
Features
The SSST900-500 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.
* Small Size: 1.295” by 1.410” by 0.255”
The SSST900-500 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.
SensorOnAirTM eliminates the need for an application
controller by utilizing the communications controller to
directly manage analog inputs and digital control lines.
We also offers a low power spread spectrum model,
the SSST900-10, for applications that require less range.
The SSST900-10 has an obstructed range of 300 feet but
is smaller, costs less and uses significantly less power.
* Serial Control and Configuration of the Wireless Link.
* Supports a 254 node point-to-multipoint network
* Programmable Transmit Power Output 100 to 500 mW.
* Typical Receiver Sensitivity -100 dBm
* Obstructed signal range to 1000 feet;
* Wireless Data Rate 76.8K bps, half-duplex
* Low power Consumption
SSST900-500: 1000 mA @ 3.3 Volts; when transmitting
at 500 mW output power; less than 1 mA of current
flows in Sleep Mode or Power-Down modes
* SensorOnAirTM (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 Temperature Range of -40 to +85 C
* FCC Part 15 Registered
SSST900-500 Block Diagram
Antenna
ROM
SAW
FILTER
Serial I/F
MUX
TRANSCEIVER
COMM.
CONTROLLER
Analog
Inputs
Digital I/O
AMP
SAW
FILTER
(1)
SSST900-500
SSST900-500 MECHANICAL SPECIFICATIONS
F
E
H
Top View
G
B
I
C
A
Dimension
A
B
C
D
E
F
G
H
I
H
D
Description
Module Width
Module Length
Module Thickness
Minimum Lead Length
Antenna Width
Edge to Antenna
Pin to Pin Spacing
Edge to End of Pin Row
Pin Row Length
(2)
Inches
1.295
1.410
0.255
0.125
0.134
0.995
0.100
0.155
1.100
MM
32.89
35.81
6.48
3.18
3.40
25.27
2.54
3.94
27.94
SSST900-500
Layout PCB for SSST900-500 and SSST900-10
Despite the fact that the SSST900-500 is substantially
larger module than the SSST900-10, 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 SSST900-10 requires a separate pin row for Pins 10
through 14. These pins will be hidden under the SSST900
500 module when the larger module is installed. The
SSST900-10 also includes one unique signal, Reset.
Reset is an active high signal that can be left
unconnected if no external reset is desired.
The SSST900-500 and SSST900-10 can share board layout
because of common pin assignments. Pins 1 through 8
of the SSST900-10 are equivalent to Pins 3 through 10 on
the SSST900-500; they have the same functions and are
placed in the same sequence. Pin 9 on the SSST900-10 is
an unused pin and therefore does not conflict with the
ADC1 signal assigned to Pin 11 of the SSST900-500.
The figure below shows the overlapping layout that
supports both modules. The SSST900-500 outline and
pins are shown in green. SSST900-10 pins and outline are
shown in red.
SSST900-500/SSST900-10 Overlay
Gnd
1
Vcc
2
SSST900-500
/TXD
3/1
/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
SSST900-10
12
(3)
SSST900-500
Using the SSST900-500 Power Saving Modes
The SSST900-500 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 SSST900-500 operating modes.
IDLE: In Idle Mode all circuits within the SSST900-500 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 SSST900-500
are powered-down to reduce consumption. The
SSST900-500 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.
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
SSST900-500 cannot respond to incoming RF
communications requests. If a transmit RF or Receive RF
command is received, the SSST900-500 can activate the
RF section in under 200 microseconds. Current draw in
Power-Down Mode is less than 800 microamps.
RF Monitor Mode: The SSST900-500 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 SSST900-500
is actively receiving an incoming 900 MHz data signal.
Current draw in RF Receive Mode is typically 35
milliamps.
RF Transmit Mode: In RF Transmit Mode the SSST900-500
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.
AT 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)
(4)
SSST900-500
SSST900-500 PIN CONFIGURATION
GND
VCC
/TXD
/RXD
/CTS
/RTS
DIO3
DIO2
DIO1
DIO0
ADC1
ADC0
1
2
3
4
5
6
7
8
9
10
11
12
SSST900-500
Top View
SIGNAL
PINS
DESCRIPTION
Ground
1
Common voltage reference for the SSST900-500.
VCC
2
3.3 Volt power for the SSST900-500.
/TXD
3
Transmit Data is the data input to the SSST900-500
/RXD
4
Received Data is the data output from the SSST900-500.
/CTS
5
Clear to Send provides hardware flow control from the SSST900-500. The SSST900-500
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 SST900-500 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 SSST900-500.
DIO2
8
DIO2 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the SSST900-500.
DIO1
9
DIO1 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the SSST900-500.
DIO0
10
DIO0 may be programmed as either a digital input or digital output. It connects directly to
the communications controller in the SSST900-500.
ADC1
11
Analog Input 1 to the SSST900-500 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 SSST900-500 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.
(5)
SSST900-500
ABSOLUTE MAXIMUM RATINGS
VCC
Storage Temperature
Operating Temperature Range
3.9 Volts
-55O C to +125O C
-40O C to +85O C
WARNING: Exceeding any of these ratings will void the warranty and may damage the device
SSST900-500 ELECTRICAL SPECIFICATIONS
Parameter
VCC
Min
Typ
Max
Units
2.7
3.3
3.6
Volts
Transceiver power
1000
mA
Transmit (500 mW output)
0.8
0.10
mA
mA
mA
mA
mA
mA
mA
mA
Receive Mode
Idle Mode
Avg; 2-sec RF Monitor interval
Avg; 4-sec RF Monitor interval
Avg; 8-sec RF Monitor interval
Avg; 16-sec RF Monitor interval
Power-Down Mode
Sleep Mode
500
mW
50 Ohm Load
ICC
35
23
2.2
1.1
0.6
0.3
Output Power:
100
Wireless Receive Sensitivity
-100
dBm
Range thru Physical Obstructions
1000
feet
Frequency Hopping Channels
Frequency Band
902
Vil
928
50
MHz
Ohms
2.25
Vol
Vih
500 mW output
50
Antenna Output Impedance
Voh
Comments
0.75
2.25
0.75
(6)
Volts
VCC =3.3 Volts
Volts
VCC =3.3 Volts
Volts
VCC =3.3 Volts
Volts
VCC =3.3 Volts
SSST900-500
SSST900-500 TYPICAL CONNECTION DIAGRAM
3.3V
Antenna
C1 C2 C3
C4
C5
GND
L1
VCC
/TXD
Host
Serial
I/F
/RXD
/CTS
/RTS
DIO3
DIO2
DIO1
DIO0
ADC1
ADC0
Parts List for SSST900-500 Typical Connection Diagram
Reference
Designation
Qty
Description
C1
1
Capacitor, Electrolytic, 100 ufd, 10 Volts
C2, C4
2
Capacitor 0.1 ufd, 10 Volts
C3, C5
2
Capacitor 47 pfd, 10 Volts
L1
1
Coilcraft 0603HC-7N5XJB
Antenna *
1
50 Ohm, 1/4 Wave;
* The Antenna connector on SSST900-500 models is a Male MMCX
connector. An female MMCX to Female SMA adapter is needed for
the antenna connection
(7)
SSST900-500
SSST900-500 COMMUNICATIONS CONTROLLER
The SSST900-500 uses an internal micro-controller to
control communications. This micro-controller manages
the interface to the host system, determines when the
communications link is available, and formats data for
the RF communications.
Command Prefix - Each command, except the A/
command, begins with the AT prefix. The "A" and "T"
may be either both upper case or both lower case but
cannot be of different cases. The prefix identifies parity of
the commands sent to the SSST900-500 by comparing the
parity bits of the "A" and the "T" characters.
HOST INTERFACE
The SSST900-500 has two primary interfaces to the system
host; the serial interface and the direct sensor interface
supported by the SensorOnAir™ feature. Management
of both interfaces is the responsibility of the
communications controller.
Command Line - Commands may be strung together in a
single command line of up to 30 characters. Commands in
the command string are executed in the sequence they
appear.
RS232 Interface
The SSST900-500 supports a 4-signal serial interface. For
most applications the SSST900-500 will act as a DCE. Control
and configuration of the SSST900-500 takes place through
the serial interface using modem-like AT commands. The
serial data rate is configurable from 1200 bits per second
to 115.2K bits per second. The supported serial interface
signals are listed below.
/TXD - Transmit Data; the input to the SSST900-500 for
AT commands and Data to be transmitted on the
wireless network.
/RXD - Received Data; the output from the SSST900-500
for received RF data and responses to AT
commands.
/RTS - Request to Send, provides the hardware flow
control input to the SSST900-500. The DTE
removes RTS to stop the SSST900-500 from
sending more data on the RXD line.
Omitted Parameters - Most commands include a
parameter which determines the function setting. When
the command parameter is omitted from the command
string, it is assumed to be a 0.
Result Codes - A result code is normally issued after each
action. Result codes may be provided as full words, one
or two digit numeric codes, or may be disabled all
together. Each result code ends with a carriage return
when numeric result codes are chosen. When full word
result codes are chosen, a Line Feed and Carriage Return
precede and follow each result code.
Disconnect Sequence - A three character sequence
initiates a disconnect of the wireless link. The sequence
“~~~” is assigned to disconnect the link.
DIRECT CONNECTION OF SENSORS:
SensorOnAir™
Sensors can be connected directly to the SSST900-500
without requiring an applications controller. In this
SensorOnAir™ configuration the SSST900-500
communications controller controls the operation of the
sensors.
/CTS - Clear to Send, is the hardware flow control output
from the SSST900-500. The SSST900-500
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
SSST900-500. This includes 2 analog inputs, ADC0 and
SSST900-500 AT Command Format
AT commands issued to the SSST900-500 follow a strict ADC1, and 4 digital I/O lines, DIO0, DIO1, DIO2, and DIO3.
ADC0 and ADC1 are connected to a 12-bit analog to digital
format. Each command begins with the prefix AT and
converter and use a 2.5 volt reference derived from VCC
ends with a carriage return. TheSSST900-500
as their reference voltage. The digital I/O lines can be
communications controller accepts commands at data
programmed to act as either inputs or outputs.
rates from 1200 to 115,200 bps. The default serial data
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.
(8)
SSST900-500
SSST900-500 COMMUNICATIONS CONTROLLER
Configuring the SSST900-500 for Sensor Operation
All SensorOnAir control functions for the analog inputs
and digital I/O’s are performed by the communications
controller within the SSST900-500. Modem-like AT
commands loaded through the serial interface, program
the functions of the analog and digital I/O lines. The AT
commands used to program the SensorOnAir functions
are then stored in the SSST900-500 Flash memory. This
allows the SSST900-500 to be first programmed and then
installed in the application. The communications
controller uses the information stored in Flash memory to
control the analog and digital I/O lines.
SensorOnAir Commands™
Below is a list of the AT commands used to program the
direct control of sensors using the communications
controller in the SSST900-500.
S107 -
Defines the function of the programmable I/O lines.
The two analog input lines, ADC0 and ADC1, can
also be defined as digital I/O lines if needed. The four
programmable digital I/O lines, DIO0, DIO1, DIO2,
and DIO3; can be set as either inputs or outputs. The
value of this command is stored in flash memory within
the SSST900-500.
AT&IAn? - This command allows a local host to read the value
of Analog Input “n.”
AT&IDn? - This command allows a local host to read the
status of Digital I/O “n.”
AT&IDn=z - This command allows a local host equipment to
set the condition of the local digital output “n.” When
z=0 the output is set to a logic low; when z=1 the
output is set to a logic high.
AT#IxxxAn? - This command allows the value of Analog Input
“n” on node address “xxx” to be read remotely.
AT#IxxxDn? - This command allows the status of Digital I/O
“n” on node address “xxx” to be read remotely
AT#IxxxDn=z - This command allows the condition of the
local digital output “n” on node address “xxx” to be
set remotely. When z=0 the output is set to a logic
low; when z=1 the output is set to a logic high.
WIRELESS COMMUNICATIONS
The communications controller manges the RF Link. This
includes the frequency hopping algorithm for spread
spectrum operation; collision avoidance, node
addressing, and packetizing data. The communications
controller allows support for point-to-point, point-tomultipoint or multipoint networks.
Carrier Sense Multiple Access (CSMA)
To prevent collisions between network nodes the
SSST900-500 uses a Carrier Sense Multiple Access protocol
for each network transceiver. In normal communications
all nodes, including the Master node in a point-toMultipoint network, listen for communications activity
before initiating a session. If a wireless link already exists,
the transceiver waits until that session is complete before
initiating a wireless link.
Data Packets
All data presented by the system host is placed into
packets by the SSST900-500 communications controller
for transmission across the wireless link. These packets
provide addressing and error correction for the wireless
communications. The communications controllers place
the data in packets only for the wireless link. The data is
extracted from the packets before being sent out the serial
interface.
File Transfer Mode
SSST900-500 incorporates a File Transfer mode
that uses a simplified networking protocol so that the
maximum data transfer rate is achieved. In this mode the
SSST900-500 does not automatically retransmit blocks
containing errors. A CRC 16 checksum is calculated,
transferred at the end of the file, and checked by the
receiving unit. An “ERROR” message is displayed if the
checksum calculated at the receive end does not match
the checksum transmitted with the data.
The File Transfer Mode is controlled by the AT#T
command. The format of the command is AT#Txx; where
xx is the destination address of the file. Following is a
sample file transfer.
(9)
SSST900-500
SSST900-500 COMMUNICATIONS CONTROLLER
Sample File Transfer
Transmitter
TXD
RXD
AT#T01<cr>
:<cr>
abc...z
3 sec pause in data
Receiver
TXD
RXD
Description
Initiate File Transfer
Link Established
File Data
Checksum at End of File Transfer
File Transfer Successful
FILE<cr>
abc...z
A718<cr>
OK<cr>
or
ERROR<cr>
Error Detected in File Transfer
Notes: The above example shows that the file transfer is assumed to be completed if three seconds pass with no data
being presented to the TXD input on the serial port.
File Transfer Mode cannot be used to send binary data.
Multipoint Network
System designers using the SSST900-500 can create a point-to-multipoint network with up to 125 remote nodes. The
master node is assigned address 1. The remote nodes are assigned address from 2 to 126. We created Count-Off
to insure efficient network operation. Count-Off allows the master node to poll the entire network in less than 10
seconds. The Count-Off creates a temporary time division multiplexing scheme which permits each node to report its
status without the handshaking sequence normally required for a wireless data exchange.
The Count-Off sequence is initiated by the AT#C command from the host system. The Master node broadcasts the
Count-Off command to all network nodes. Upon receipt of the Count-Off broadcast each remote node initializes an
internal timer. Then in sequence by address each node sends an 8-byte status message to the Master. The status
message is programmed with the AT#E: or AT#E= command. Due to difficulties in synchronizing the spread spectrum
signals, a node may sometimes miss the Count-Off command. The network administrator should poll any node that
does not respond to the Count-Off request to insure the network integrity
Using Count-Off network reporting will be completed in less than 10 seconds. Based on the status information the host
can then elect to service any of the remote nodes.
COUNT-OFF™ SEQUENCE
Node 1
Node n
Node 1
Node 2
Node 9
Node n
Node 3
Node 9
Node 4
Node 8
Master
Node 2
Node n
Node 3
Node 9
Node 4
Node 8
Master
Node 8
Node 7
Node 1
Node 5
Node 6
T0 - Master Broadcasts
Count-Off Initiation
Node 7
Node 1
Node 2
Node n
Node 3
Node 9
Node 4
Node 8
Node 3
Master
Node 5
Node 7
Node 6
T1 - Node 1 Transmits
8-Byte Status
Node 2
Master
Node 5
Node 6
T2 - Node 2 Transmits
8-Byte Status
Node 4
Node 7
Node 5
Node 6
Tn - Node n Transmits
8-Byte Status
Count-Off Complete
(10)
SSST900-500
AT COMMANDS
An asterisk indicates the factory default
&IDn? Read Local Digital Input “n” - This command allows
the host equipment to read the status of the local digital
inputs.
A
Answer Command - forces the smart transceiver
respond to a summons from another wireless device.
Dn
Initiate a Wireless Link - attempts to establish a
connection with the transceiver at address n.
n=1 Read input DIO1
En
Echo Characters - determines if the SSST900-500 will
echo the characters received on its serial interface during
command mode.
n=3 Read input DIO3
n=0 Characters not Echoed
n=5 Read input DIO5 (pin shared with ADC1)
n=1 Characters Echoed *
In
Identification - displays product identification code.
n=0 Display Product Code
Qn
n=0 Read input DIO0
n=2 Read input DIO2
n=4 Read input DIO4 (pin shared with ADC0)
&IDn=z Set Local Digital Output “n” - This command
allows the host equipment to set the condition of the
local digital outputs. When z=0 the output is set to a
logic low; when z=1 the output is set to a logic high.
n=1 Display Product Name
n=0 Set output DIO0
n=2 Display Model Number
n=1 Set output DIO1
n=3 Display Copyright
n=2 Set output DIO2
n=4 Display Firmware Revision
n=3 Set output DIO3
Result Code Display - determines if result codes will
be displayed.
&Kn Flow Control - selects the type of flow control to be
used between the system host and the SSST900-500
n=0 Display Result Codes *
n=0 Flow Control Disabled
n=1 Do not Display Result Codes
n=3 RTS/CTS, hardware Flow Control
n=4 XON/XOFF, in-band Flow Control
Sn= Set Value of Register Sn
Sn? Read Value of Register Sn
Vn
Response Type - selects Full Word or Numeric
responses
n=0 Numeric Responses
Zn
&V
&Wn Store Current Configuration - loads the current
SSST900-500 configuration into either User Profile 0 or
User Profile 1.
n=1 Full Word Responses *
n=0 load configuration into User Profile 0
Reset - executes a soft Reset
n=1 load configuration into User Profile 1
n=0 Reset to Values Stored in User Profile 0 *.
#B
Wireless Broadcast Mode - initiates wireless broadcast
mode for diagnostic purposes.
#C
Count-Off Request (ASCII) - Initiates a “count-off’
sequence in the network with node status to be reported
in ASCII format.
#E:
Count-Off Response (ASCII) - Programs the nodes 8
byte response to a “count-off’ request from the network
hub in ASCII format.
#E=
Count-Off Response (Hex) - Programs the nodes 8
byte response to a “count-off’ request from the network
hub in hexadecimal format.
n=1 Reset to Values Stored in User Profile 1
&F
View Active Configuration - sends the active
configuration data to the system host.
Restore Factory Settings - returns all configuration
commands and registers to their factory default values.
&IAn? Read Local Analog Input “n” - This command allows
the host equipment to read the values of the local analog
inputs.
n=0 Read input ADC0
n=1 Read input ADC1
(11)
SSST900-500
AT COMMANDS
#IxxxAn? Read Analog Input “n” at Node Address xxx This command allows analog input values at any node
to be read remotely.
n=0 Read input ADC0
n=1 Read input ADC1
#IxxxDn=z Set Digital Output “n” at Node Address xxx
- This command allows the condition of the digital
outputs to be modified remotely. When z=0 the
output is set to a logic low; when z=1 the output is set
to a logic high.
n=0 Set output DIO0
#IxxxDn? Read Digital Input “n” at Node Address xxx This command allows the status of the digital inputs at
any node to be read remotely.
n=1 Set output DIO1
n=2 Set output DIO2
n=3 Set output DIO3
n=0 Read input DIO0
n=1 Read input DIO1
#Pn
n=2 Read input DIO2
Low Power Operation - Allows the SSST900-500 to
operate in reduced power modes.
n=3 Read input DIO3
n=0 Selects Normal Power Mode
n=4 Read input DIO4 (pin shared with ADC0)
n=1 Places Transceiver in Sleep Mode;
n=5 Read input DIO5 (pin shared with ADC1)
n=2 Places Transceiver in Power-Down Mode
#R
Receive Broadcast - Allows SSST900-500 to receive a
broadcasted message and present it on the serial
interface.
#Txx File Transfer - initiates a file transfer to the
destination address xx.
SSST900-500 Responses
Numeric
Full Word
Description
0
OK
1
CONNECT RF
Wireless Connection Established
2
RING
Wireless Link Request Detected
3
DISCONNECT
4
ERROR
6
NO CONNECTION
7
BUSY
Link Request Time Out has occurred
8
SORRY
No Response to Count-Off Request
9
WAIT
Wireless Link is not available
FILE
File Transfer Mode
Successfully executed command line
Lost Wireless Link
Error in command line, or file transfer
Failed to Establish Wireless Link
(12)
SSST900-500
SSST900-500 Configuration Registers
S0
Answer Wireless Link Request: S0 determines if the
SSST900-500 will automatically respond to a wireless
link request.
S23 Serial Interface Data Rate - S23 stores the serial
interface data rate.
Range 1-10
S0=0
No Automatic response to link requests
1 = Set serial data rate to 1200 BPS
S0=1
Automatically respond to link requests
2 = Set serial data rate to 2400 BPS
S0=128 Enter Broadcast mode on power-up. The
command must be stored in nonvolatile
memory using the AT&W command.
3 = Set serial data rate to 4800 BPS
4 = Set serial data rate to 9600 BPS*
5 = Set serial data rate to 14400 BPS
S2
Wireless Disconnect Character - S2 sets the ASCII
character to be used in the link disconnect sequence.
The default character is the tilde “~”.
Range:
6 = Set serial data rate to 19200 BPS
7 = Set serial data rate to 28800 BPS
8 = Set serial data rate to 38400 BPS
0-255
9 = Set serial data rate to 57600 BPS
Default: 126
S7
Link Set-up Timer - S7 sets the length of time in
seconds that the transceiver will attempt to create a link
with the destination node.
Range:
0-60
Default:
10
S10 Link Recovery Timer - S10 sets the length of time in
seconds that the transceiver tries to recover a broken
link.
10 = Set serial data rate to 115200 BPS
Default: 4
S39 Bit-mapped Register - S39 stores the value of the AT&K
command.
S104 Group ID Number - S104 sets the Group ID number for
the SSST900-500. Up to “n” groups may be active in the
same area. Only transceivers with the same Group ID
number can communicate.
Range:
0-60
Range:
Default:
10
Default: 0
S12 Disconnect Guard Timer - S12 sets the guard timer in
milliseconds before and after the disconnect sequence.
If any characters other than the disconnect sequence are
received within the window defined by S12 the
disconnect request will be ignored..
Range:
0-255
S105 SSST900-500 ID Number -S105 sets the ID number for
the SSST900-500. Each unit on the Base Access Network is
required to have a unique ID number.
Range:
1-254
0-255
Default: 20
Units:
Milliseconds
S14 Bit-mapped Register - S14 stores the values of the
ATE, ATQ and ATV commands.
(13)
SSST900-500
SSST900-500 Configuration Registers
S107 I/O Configuration - S107 is a bit-mapped register
which defines the local programmable I/O lines.
S108 Transmit Level Control - S108 sets the transmit level
Range:
0-3
Bit 0 = 0 - ADC0 and ADC1 used as Programmable I/O
= 1 - ADC0 and ADC1 defined for Analog use
0
20 dBm
1
23 dBm
Bit 1 = reserved
2
26 dBm
Bit 2 = 0 - DIO0 used as an output
= 1 - DIO0 used as an input
3
27 dBm
Default: 3
Bit 3 = 0 - DIO1 used as an output
= 1 - DIO1 used as an input
Bit 4 = 0 - DIO2 used as an output
= 1 - DIO2 used as an input
Bit 5 = 0 - DIO3 used as an output
= 1 - DIO3 used as an input
Bit 6 = 0 - DIO4 used as an output (Bit 0 = 0)
= 1 - DIO4 used as an input
Bit 7 = 0 - DIO5 used as an output (Bit 0 = 0)
= 1 - DIO5 used as an input
Default: 193
(14)
SSST900-500
FCC PART 15 REGULATIONS
Mounting the SSST900-500 in Your Assembly
The SSST900-500 must be mounted horizontally on your
printed circuit board to maintain proper orientation of
the transceiver. Standoffs should also be used on the
side opposite the pin row to maintain clearance
between the SSST900-500 and you printed circuit board.
The SSST900-500 may not be co-located with any other
antenna or transmitter.
Warning: RF Exposure
The SSST900-500 is approved for mobile, base station
and mobile applications. A minimum separation of 20
centimeters should be maintained between the antenna
and the equipment operator. For mobile applications
check the minimum separation distances defined below.
To ensure compliance, operation at distances closer
than those defined is not recommended.
SSST900-500 Antenna
The SSST900-500 is certified for compliance to FCC Part
15 rules only using the SSST900-500, 1/4 wave
monopole antenna. Use of any other antenna violates
FCC Part 15 rules.
The Warning message below must be included in the
user Manual for the end product.
FCC Part 15 Certification
The SSST900-500 has been certified per FCC Part 15 rules
for integration into OEM products without further
testing or certification. This certification is your
assurance that the SSST900-500 will not cause harmful
interference.
Labeling Requirements
FCC rules require the Original Equipment Manufacturer
using the SSST900-500 to place an appropriate label on
the outside of the finished equipment. The label must
be clearly visible and include the information shown
below.
Contains Transmitter Module
FCC ID: DWE-SSST900-500
WARNING:
This device complies with Part 15 of the FCC Rules.
Its operation is subject to the following conditions:
(1) This device may not cause harmful interference.
(2) This device must accept any received interference
including interference that may cause undesired
operation.
To comply with FCC RF exposure requirements
for mobile transmitting devices, this transmitter
should only be used or installed at locations where
there is at least 20 cm separation distance between
the antenna and all persons.
FCC Notifications
The SSST900-500 generates radio frequency energy. It
must be installed according to the manufacturer’s guidelines stated in the data sheet or it has the potential to
cause interference with other radio devices. Testing has
been performed to assure that it conforms with the FCC
Part 15 rules for intentional and unintentional radiators.
No further EMI compliance testing of the transmitter is
required as long as the 20 cm separation and co-location
requirements are observed. Each new use of the module
will, however, need to be scanned for unintentional radiation from digital clocks, etc.
All necessary calibration has been performed at the time
of manufacture. Any modification of the device after it
leaves the factory is a violation of FCC rules.
Limitations
The SSST900-500 is registered under FCC Part 15 Rules.
To utilize this registration on your OEM System you
must follow the applications circuit provided in this
data sheet and use one of the listed antennas. Any
changes or modifications to the recommended circuit
must be approved
(15)
SSST900-500