LX2400S Transceiver PRELIMINARY Specifications Subject to Change Hardware and Software Interface Specification Version 3.3 13256 W. 98th Street Lenexa, KS 66215 (800) 492-2320 Fax (913) 492-1243 www.aerocomm.com wireless@aerocomm.
Copyright Information/FCC User’s Notice Copyright Information Copyright © 2000 AEROCOMM , Inc. All rights reserved. The information contained in this manual and the accompanying software programs are copyrighted and all rights are reserved by AEROCOMM , Inc. AEROCOMM , Inc. reserves the right to make periodic modifications of this product without obligation to notify any person or entity of such revision.
ANTENNA WARNING WARNING: This device has been tested with an MMCX connector with the antennas listed below. When integrated in the OEMs product, these fixed antennas require installation preventing end-users from replacing them with non-approved antennas. Any antenna not in the following table must be tested to comply with FCC Section 15.203 for unique antenna connectors and Section 15.247 for emissions.
RF EXPOSURE OVERVIEW MinimumR F Exposure Distance (cm) LX2400-150 LX2400-10 LX2400-3 SAR Specifications with Body Tissue (W/Kg) Antenna Manufacturer Part Number Type Gain Applicatio n* Centurion WCP-2400-MMCX 2dBi P/M/F N/A 0.400 30 Maxrad MC2400 ¼ Wave Dipole Patch 2.5dBi F N/A N/A AeroComm NZH2400-MMCX (External) Microstrip 1dBi P N/A 0.308 30 30 AeroComm NZH2400-I (Integrated) Microstrip 1dBi P 0.057 N/A N/A Nearson S131CL-5-RMM-2450S 2dBi P/M/F N/A 0.
Revisions Version 1.0 Description Initial Release Version - 01/20/2000 Version 2.0 Not Released Version 3.0 Release Version - 2/15/2000 Full Document Update – major changes: 1. The Transmit Sync byte has been changed 2. The previous version called out RTS rather than TE for the Transmit Enable pin. This has been corrected Version 3.1 Release Version - 5/23/2000 1. Corrected Serial Interface data rate to 57,600bps maximum 2. Add specifications on LX2400S-10 and LX2400S-10A 3.
CONTENTS TABLE OF CONTENTS 1. OVERVIEW ............................................................................................................................................................. 7 2. LX2400S SPECIFICATIONS .............................................................................................................................. 8 3. THEORY OF OPERATION ................................................................................................................................
OVERVIEW LX2400S FEATURES • Simple 5V TTL level serial interface for fast integration • Integrated Antenna saves space and reduces cost • Frequency Hopping Spread Spectrum for security and interference rejection • Cost Efficient for high volume applications • Low power consumption for battery powered implementations • Small size for portable and enclosed applications 1. Overview The LX2400S is a member of AeroComm’s ConnexRF OEM transceiver family.
SPECIFICATIONS 2. LX2400S Specifications GENERAL Interface Serial Interface Data Rate (See 3.2.6.1.3 & 3.2.6.1.4) Power Consumption Transmit/Receive Channels (used to create independent networks) Security 20 pin mini-connector, See mechanical drawing.
THEORY OF OPERATION 3. Theory of Operation 3.1 Interface Signal Definition The LX2400S has a simple interface that allows OEM Host communications with the transceiver. Table 1 shows the connector pin numbers and associated functions. The I/O direction is also shown. The direction is with regard to the transceiver. All I/O is 5Vdc TTL level signals except for RSSI. All outputs are weakly pulled high (20k – 50k ohms) when left unconnected and are driven high at reset.
THEORY OF OPERATION 3.2 Host Software/Hardware Interface Definition 3.2.1 Host Transmit Frame Format The LX2400S requires the following format in order to transmit a Host’s data packet over the RF link. The frame consists of 3 bytes of preamble, 1 sync byte, a 16-bit length, and user data.
THEORY OF OPERATION 3.2.4 In Range The IN_RANGE pin at the connector will be driven low when a Client radio is in range of a Server on the same channel. If the Client cannot hear a LX2400S Server for 10 S, the LX2400S Client drives the IN_RANGE pin high and enters a search mode looking for a LX2400S Server. As soon as it detects a Server, the IN_RANGE pin will be driven low. The LX2400 Server can determine what Clients are in range by the Server’s Host software polling the LX2400S Client’s Host. 3.2.
THEORY OF OPERATION 3.2.6 LX2400S Configuration Parameters and Commands 3.2.6.1 Configuration Parameters The Host can program various parameters. The data is stored in EEPROM and becomes active on the next power on reset of the LX2400S. Table 2 gives the locations and functions of the parameters that can be read or written by the Host. Factory default values are also shown. Note: Non-Host parameters are used in the EEPROM. The Host must only write to the locations in Table 2.
THEORY OF OPERATION 3.2.6.1.2 CHANNEL parameter The LX2400S can be programmed to one of ten different channels. Client mode transceivers will receive and transmit to a Server on the same channel as programmed. Servers will receive and transmit to Clients on the same channel as programmed. CHANNEL can be programmed with a value ranging from 0 to 9. 3.2.6.1.3 BAUDRATE parameter This two-byte value determines the baud rate used for communicating over the serial interface to the LX2400S.
THEORY OF OPERATION 3.2.6.1.5 CONTROL parameter The individual bits in the control byte alter the operation of the LX2400S. The Bit definitions follow: Bit 0 – Controls if the LX2400S sends XON and XOFF characters to the Host, XOFF at the start of the HOP and XON at the end of the HOP. Bit 1 – Controls if the LX2400S uses the RE pin on the connector to enable Host communications. Bit 2 – Reserved for future use, always cleared to 0.
THEORY OF OPERATION 3.2.6.2.3 EEPROM BYTE WRITE command The write routine includes the write command, address, length, and data bytes. Upon receiving this command, the LX2400S will write the data byte to the address specified but will not echo it back to the Host until the EEPROM write cycle is complete. The write can take as long as 10ms to complete. Following the write cycle, the LX2400S will transmit the data byte to the Host.
THEORY OF OPERATION 3.2.7.3 Effective Data Transmission Rate The maximum Effective Data Transmission Rate (EDTR) is defined as the rate of one-way continuous transmission of data packets sent by a Host. It includes the transmitter turn-on and turn-off delays, HOP time, Host data byte timing and the number of bytes per packet sent by the Host. Beacon timing is not used in this calculation -- since it is only transmitted when data has not been received by the LX2400S from the Host for approximately 2.
THEORY OF OPERATION The following examples give OST for 3 different systems and uses the values from the previous section. Other systems are possible: 1 – POSITIVE ACK SYSTEM -- An acknowledgement response packet for each packet received. Additional example data: NHRD = Number of Host system response bytes = 3 (e.g. command and two address bytes) Calculations: PKT = Packet time = (NPSL + NHSD + NHED) * (IBT + IGT) = 35.07ms RSPT = Response time = (NPSL + NHRD + NHED) * (IBT + IGT) = 2.
INTERFACIING TO THE LX2400 4. Interfacing to the LX2400S 4.1 OPERATING MODES The LX2400S uses an 8-bit programmable asynchronous serial interface to communicate to a Host. The interface uses one start bit, eight data bits, and one stop bit. Only the interface baud rate is programmable by the Host. A typical system consists of one LX2400S operating in Server Mode (LX2400S Server) communicating with one or many LX2400S(s) operating in Client Mode (LX2400S Client).
INTERFACIING TO THE LX2400 4.1.3 CONFIGURATION MODE The CONFIGURATION MODE is used to read and write the EEPROM -- allowing the Host to set channels, baud rates, etc. See TABLE 2. While in this mode the LX2400S will not receive any data over the RF link. TE and CTS are not used. The Host enters this mode with the following sequence: 1. 2. 3. 4. 5. 6. 7. The Host pulls the TST_MODE pin low. The Host sends the CONFIGURATION START BYTE to the LX2400S. The Host pulls the WR_ENA pin low if writing.
INTERFACIING TO THE LX2400 4.2 LX2400S GLOBAL Timing Parameters Table 4 – Global Timing Parameters Timing is preliminary and not guaranteed for production NAME tRT tTR tTXMOD tPackG tByteG MIN TYP TBD TBD Max 1ms 1ms 20ms 1ms 1 byte time COMMENT Receive to Transmit settling time – Transmit Off Transmit to Receive settling time – Transmit Off Longest amount of time to continuously send data TX Packet Gap Maximum Byte Gap 4.
INTERFACIING TO THE LX2400 4.
INTERFACIING TO THE LX2400 Table 7 – Hopping and Beacon Timing NAME D0 D1 D2 D3 D4 D5 D6 09/22/00 Preliminary MIN TYP MAX 100ms 1ms 1ms 1ms 1ms 20ms 1ms COMMENT Timing is preliminary and not guaranteed for production Timing is preliminary and not guaranteed for production Timing is preliminary and not guaranteed for production Timing is preliminary and not guaranteed for production Timing is preliminary and not guaranteed for production Timing is preliminary and not guaranteed for production Timing i
MECHANICAL 5. Mechanical Overview 5.1 Transceiver The LX2400S measures 1.65” x 2.65”. Critical parameters are as follows: J1 – 20 pin connector (lower left edge) SAMTEC TMM-110-01-L-D-SM (4) Mounting holes are 0.100” diameter. Figure 1. Mechanical Overview of LX2400S 5.2 Antenna The LX2400S-3A and the LX2400S-10A incorporate an Aerocomm NZH antenna on the transceiver board. The NZH is a highly efficient, microstrip, center-fed dipole design with a broad pattern.
ORDERING INFORMATION 6. Ordering Information 6.1 Product Part Numbers LX2400S-3, LX2400S with 3mW output power, interface data rates to 19,200bps, integrated antenna LX2400S-10, LX2400S with 10mW output power, interface data rates to 57,600bps, MMCX ant connector LX2400S-150, LX2400S with 150mW output power, interface data rates to 115,200bps, 6.
