XE5690SM Datasheet, PDF (8/16 Pages) List of Unclassifed Manufacturers – Compact, Low-Cost Global Embedded Modem

XE900S-500 COMMUNICATIONS CONTROLLER
The XE900S-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.
HOST INTERFACE
The XE900S-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.
RS232 Interface
The XE900S-500 supports a 4-signal serial interface. For
most applications the XE900S-500 will act as a DCE. Control
and configuration of the XE900S-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 XE900S-500 for
AT commands and Data to be transmitted on the
wireless network.
/RXD - Received Data; the output from the XE900S-500
for received RF data and responses to AT
commands.
/RTS -
Request to Send, provides the hardware flow
control input to the XE900S-500. The DTE
removes RTS to stop the XE900S-500 from
sending more data on the RXD line.
/CTS - Clear to Send, is the hardware flow control output
from the XE900S-500. The XE900S-500
deactivates Clear to Send to advise then host to
stop inputting data on the TXD lead.
XE900S-500 AT Command Format
AT commands issued to the XE900S-500 follow a strict
format. Each command begins with the prefix AT and
ends with a carriage return. The XE900S-500
communications controller accepts commands at data
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.
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 XE900S-500 by comparing the
parity bits of the "A" and the "T" characters.
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.
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 XE900S-500
without requiring an applications controller. In this
SensorOnAir™ configuration the XE900S-500
communications controller controls the operation of the
sensors.
Sensor I/O Lines
SensorOnAir controls the operation of 6 I/O lines to the
XE900S-500. This includes 2 analog inputs, ADC0 and
ADC1, and 4 digital I/O lines, DIO0, DIO1, DIO2, and DIO3.
ADC0 and ADC1 are connected to a 12-bit analog to digital
converter and use a 2.5 volt reference derived from VCC
as their reference voltage. The digital I/O lines can be
programmed to act as either inputs or outputs.
XECOM
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XE900S-500