SX450G TRANSCEIVER OPERATING INSTRUCTIONS 1892 1344 These operating instructions are intended to provide the user with sufficient information to install and operate the unit correctly. The Wood & Douglas SX450G is a high-performance synthesized UHF transceiver for use in radio telemetry applications. The transceiver provides a maximum power output of 500mW and is designed to meet European standards ETS 300 220, ETS300 086 and ETS300 339.
Contents Part One The SX450G Radio Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 DIMENSIONS AND FIXING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 POWER SUPPLY AND CURRENT CONSUMPTION . . . . . . . . . . . . . . . . . . . . . . 8 CHANNEL SELECTION DURING OPERATION . . . . . . . . . . . . . . . . . . . . .
Part One The SX450G Radio Unit v Part Two, Programming, starts on page 13 1892 1344 - SX450G Transceiver Operator Guide v1.
1892 1344 - SX450G Transceiver Operator Guide v1.
DIMENSIONS AND FIXING The SX450G is intended to fit easily and with minimum space requirements into the user's own equipment housing. Figure 1 SX450G fixing detail Figure 2 - SX450GA connectors Figure 3 - SX450GC connector SX450GA mating connectors: 12W mating connector is MOLEX 51021-1200 with 50079 crimps. 8W mating connector is MOLEX 51021-0800 with 50079 crimps. One each of these connectors, mounted onto a 200mm flying lead, is supplied with each unit.
The four corner tabs of the enclosure can be folded out to provide alternative mounting of the unit, with fixing centres of 93.00 x 47.5mm using four M2 screws. Figure 4 - Alternative mounting dimensions 6 1892 1344 - SX450G Transceiver Operator Guide v1.
CONNECTIONS The radio antenna connects via an MMCX 50O socket. All other connections to the SX450GA transceiver are made via a 12-way connector PL1 and an 8-way connector PL2. These are single-in-line plugs which mate with the freeissued connectors with flying leads. All other connections to the SX450GC transceiver are made via a 21-way SIL PCB connector, PL1. SX450GA SX450GC NAME PL1-1 PL1-1 0V PL1-2 PL1-2 PL1-3 FUNCTION REMARKS 0 volts common ground STBY standby input LOW (<+0.
PL1-12 PL1-12 CS5 PL1-13 - channel select input (MSB) not connected RF DET TX RF present flag output - PL2-1 PL1-14 PL2-2 PL1-15 PL2-3 PL1-16 SQO squelch flag output NPN open collector via 470O; ON = no signal, OFF = signal present.
OVERVIEW OF FREQUENCIES AND PROGRAMMING Each radio is built to order to cover a band (the switching bandwidth) of 20MHz within the range 400 - 470 MHz. Each radio is also manufactured to work with a particular channel width of 12.5kHz, 20kHz or 25kHz. These are fixed parameters, and cannot be changed by the user.
CHANNEL SELECTION DURING OPERATION There are three ways to select a channel during operation: v v v In hardware, using six logic lines to select channels 0-63 Using the SXn50.EXE software and a serial connection from a PC to the unit By sending a short serial data message to the unit from your own equipment. Parallel Channel Selection v Whenever PL1 pin 6 , Mode Select, is logic high (>2.
Serial Channel Selection v PL1 pin 6 must be logic low (<0.8V) to specify serial channel selection. This is automatically the case when connected to an idle RS232 data output. v Channels 0 - 255 are available in this mode The channel can be changed by sending a serial channel number as a single RS232 byte on PL1 pin 6. The SXn50.exe software has the ability to do this, or you can use your own equipment. A simple adaptor such as the one in Figure 6 can be used to connect a PC to the unit.
When in this mode, the unit operates on the channel most recently selected in serial mode. This setting is remembered during unit power off and any period of parallel channel selection. One way to send such a byte is to use a terminal such as a VT100 or emulator. Appendix 3 on page 28 shows the keystrokes necessary to generate the appropriate binary codes for channels 0 to 127.
Part Two Programming 1892 1344 - SX450G Transceiver Operator Guide v1.
1892 1344 - SX450G Transceiver Operator Guide v1.
CONNECTING THE UNIT TO A PC FOR PROGRAMMING In order to program the unit, the unit and a PC (IBM-compatible personal computer) must communicate via an asynchronous RS232 serial link. The adaptors shown in the Appendix 1 on page 25 provide this link. A simple adaptor for the SX450GA like that shown in Figure 10 can be purchased from Wood & Douglas, product code 01106 1503 A. If your computer does not have an RS232 serial port, then a USB-to-serial adaptor is required, described in Appendix 2 on page 27.
OBTAINING AND RUNNING THE PROGRAMMING SOFTWARE 1. Download the latest version of the programming software SXn50.exe from the Wood & Douglas site on the internet. The URL (address) is: www.woodanddouglas.co.uk (In case of difficulty, contact Sales at Wood & Douglas, contact details on the last page of this manual.) 2. Open the Zip file and run setup.exe, which will install the software for you. 3. Run the SXn50.EXE program. It will run in a normal window with both mouse and keyboard support.
PROGRAMMING THE UNIT Three steps are necessary: v v v Upload (read) values from the unit Edit the values Download (write) values to the unit Reading Current Unit Settings First, you must read into the computer what is in the unit’s memory at present. To do this, press F5 or select Link > Read from the Unit > Upload All from SX450G. The data replaces the defaults on the screen and fills in the unit details.
v The list displays all valid values for the starting frequency, that is, frequencies within the switching bandwidth which are multiples of the Comparison Frequency. Select a Table Start frequency from the list and a Table Step and click OK. The dialog is removed and the main table shows the channel frequencies. To set the Rx Offset for the whole table, select Parameters > Rx Offset and pick from the list of possible values.
this is determined by hardware logic lines. Otherwise it depends on the most recent serial command received, which is retained during power-down and during parallel operation. To set the operational channel, double-click on the channel number in the frequency table. The row is highlighted to indicate that this is the operational channel. Downloading New Settings to Unit As yet, the settings have only been edited in the program.
DESCRIPTION OF USER INTERFACE Top Level Menu Bar (Outer Window) File Load Parameters Load a pre-stored set of parameters in a *.WXP file from a standard File Open dialog. Save Parameters Save the current set of parameters, overwriting the previous ones. Save Parameters As Save the current set of parameters under a new name. A default name is given which you can change, and you can navigate to the directory of your choice. Saving Options Controls the format in which information is saved.
Link Read from Unit Reads data from the unit into the program, which is then displayed on the screen. Until this command has been issued, no data can be downloaded to the unit. Write to Unit Downloads data from the program to the unit. This command can only be issued after a Read from Unit command has been issued during the current session. Send e-mail Causes your default email application to create a new blank email addressed to Wood & Douglas technical support with the subject “SNx50".
Main Menu - Frequency Table (Inner Window) Channel Table The Channel Table shows the following parameters for each of the 80 or 256 channels, as appropriate: Channel No Parallel (logic lines) code required to select this channel, where 1 represents a connection to 0v, closed contact to 0V or logic low. Tx Frequency The transmit frequency. Rx Frequency The receive frequency (which may be different if an Rx offset has been selected).
TECHNICAL SPECIFICATION General Frequency range A band within the range 400-490MHz, to order Switching bandwidth 15 or 20MHz depending on band ordered. Frequency stability +2.5ppm over operating temperature Channel switching delay 100ms maximum (over 20MHz switching bandwidth) Channel programming Table of 256 equally-spaced frequencies with common RxTx offset, or table of 80 individually-programmed frequencies and Rx-Tx offsets.
Transmitter RF output power into 50O 500mW (HI) (+0/-1.5dB) 5mW (LO) TX/RX switching time <25ms Modulation input analogue digital 750mV p-p, AC-coupled +3 to +12V square wave DC-coupled Frequency response 9Hz to 3kHz at -3dB (analogue input) (optional extended response to 6kHz for 9600 baud GMSK) Frequency deviation 25kHz channel spacing 20kHz channel spacing 12.5kHz channel spacing +3.0kHz nominal (+4.0kHz max) +2.3kHz nominal (+3.0kHz max) +1.5kHz nominal (+2.
APPENDIX 1: TTL TO RS232 ADAPTOR These adaptors are used to connect a PC to the SX450G when programming a unit. Many PCs do not require true RS232, and will work with the simple adaptor of Figure 10. The transistor used must have a gain of at least 30, and the power supply must be 12V. Figure 10 - Simple programming adaptor Figure 11 shows the circuit of an adaptor providing true RS232. Figure 11 - Programming adaptor (True RS232) 1892 1344 - SX450G Transceiver Operator Guide v1.
A suitable inverting TTL to RS232 buffer circuit using the industry-standard MAX232 part is shown in Figure 12. Figure 12 - Suggested RS232 buffer circuit The MAX232 is obtainable from many component suppliers, e.g. RS Components stock no. 655-290. v 26 Note that the MAX232 has an absolute maximum supply voltage of 6V, and therefore the SX450G and the adaptor should be run from a 5V DC supply. 1892 1344 - SX450G Transceiver Operator Guide v1.
APPENDIX 2: PCS WITHOUT RS232 SERIAL PORTS (COM PORTS) Some laptops and PCs are no longer supplied with RS232 serial ports; in this case, a USB-to-RS232 adaptor can be used to connect the PC running SXn50.EXE to the SX450G. Wood & Douglas have tried a range of adaptors and recommend the EasySync US232B/LC, which has been tested with Windows 2000 and Windows XP. v 1. Further information and a downloadable manual can be found at www.easysync.co.uk/usbrs232_single.html.
APPENDIX 3: TERMINAL KEYSTROKES These keystrokes generate a serial byte output from a standard (e.g. VT100) terminal which can be used to select channels 0 to 127 in serial mode. For example, to select channel 36, key Shift+4 (dollars), which generates the byte 00100100, decimal 36. Other keystrokes may generate codes 128 to 255, depending on the terminal.
