RSX RANGE OF INTELLIGENT MODEMS USER GUIDE 1892 1139 Figure 1 - RSX Series Radio Modem Figure 2 - OEM version This manual is intended to provide you with sufficient information to install and operate an RSX radio modem correctly. 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
Contents INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Part One: Installation and Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 DIMENSIONS AND INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1 Standard Die-Cast Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.2 OEM PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION The Wood & Douglas RSX Series Radio Modems are high-speed intelligent radio modems providing a half-duplex data link over a distance of up to several kilometres, depending on the frequency chosen. They use GMSK (Gaussian Minimum Shift Keying) modulation to achieve an RF data rate of 4800 baud in a 12.5kHz channel and 9600 baud in a 25kHz channel.
1 1.1 Part One: Installation and Normal Operation DIMENSIONS AND INSTALLATION Unless supplied as an OEM PCB, the RSXn50G is supplied in a die-cast enclosure. 1.1.1 Standard Die-Cast Enclosure Dimensions and mounting by means of four off M4 holes is shown in Figure 3. Figure 3 Mounting details A whip antenna may be attached directly to the BNC connector, and in this case the unit would typically be mounted vertically.
1.1.2 OEM PCB If supplied as an OEM PCB, the unit has dimensions and mounting as shown in Figure 5. It can also be supplied with a PCB connector rather than the 9-way D-type connector shown. The unit requires a small amount of heatsinking for the on-board regulator to dissipate of the order of 2W. This is provided in the cased version by the regulator being screwed down to a supporting pillar in the diecast case.
1.2 CONNECTIONS The antenna connects by means of a 50O BNC connector on the standard unit. A 200mm coaxial flying lead is supplied with the OEM PCB. All other connections to the unit are made via a male 9-way D-type connector (optionally a 10-way IDC connector on an OEM PCB), incorporating a serial interface, supply input and a remote on/off control. This interface is used for three separate functions: radio programming, modem programming and normal operation.
1.2.2 Connections to a PC The standard version of the RSXn50 may be connected to the serial port of an IBMcompatible personal computer using the connections shown in Figure 8. Figure 8 - Connections to a PC serial port v These connections are also used when programming the modem (not the radio). If you are using a computer which has no serial port, see the Appendix on page 31 for USB to serial adaptors. 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
1.2.3 Detailed Information 9-way D-type socket 10-way IDC header Pin Pin Name Function In/out Remarks 1* 1* DCD Data Carrier RS232 Detect/Readback output +10V = signal received, squelch open -10V = no signal received, squelch closed. In radio configuration mode, Readback. 2 3 RXD Data output from RS232 modem output Serial data from modem to external device 3 5 TXD Data input to modem RS232 input Serial data from external device to modem 4 10 Input 5 to 15V DC supply (but see p.
1. 2. When the modem buffer is full When there is a signal on-channel (indicated by the squelch being active high) and transmission cannot therefore take place. When the TX squelch override is enabled, transmission is permitted, and CTS remains high.
Note: The information in this section applies to normal operation, and not to the PGM (pin 9) and Readback (pin 1) interface during radio programming. 1.2.4 Power Supply and Current Consumption The RSXn50 requires a power supply of 5 to 15V DC (12V DC nominal)2. Because the circuitry includes switched-mode power supplies, the current consumed varies inversely with input voltage, and the external power supply must be capable of supplying the corresponding current shown in the table below.
The unit normally suppresses transmission when the squelch is open, but may be configured to ignore it if required. (See page 22.) 1.3.2 LED Indications LED Figure 9 - RSX Series Radio Modem A three-colour LED visible through the top of the enclosure confirms the functional state of the modem: RED GREEN ORANGE - The modem is in transmit mode The modem is in receive mode The radio has failed (i.e. is out of lock).
2 2.1 Part Two: Programming the Radio HARDWARE LINK SETTINGS Some options may be configured to user requirements using the on-board links as detailed in the following table. With the exception of LK7, they all relate to radio operation.
The links can be found as shown in Figure 10. Figure 10 - Link Positions on RSXn50 PCB underside Links are made and broken by adding and removing a solder bridge between pads on the board as shown below. Figure 11 - Link adjustments 2.2 PROGRAMMING RADIO PARAMETERS - SXN50 The RSXn50 is normally supplied with a table of channel frequencies preset, and the radio set to use channel 0.
Alternatively, you can send single serial bytes (for example, from a terminal) to select a new channel. See page 18. Modem parameters are set separately: see page 20. 2.2.1 Programming Adaptor for use with SNx50.exe software The RSXn50 requires a special adaptor cable between itself and the PC serial port, which also connects the 5 to 15V DC supply3. This cable is shown in Figure 12. Figure 12 - Radio programming adaptor v 2.2.2 . 1.
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. At this stage, the main window is displayed as shown in Figure 13. Figure 13 - Programming screen The screen shows the default settings which are displayed whenever the software is run.
2.2.3.1 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 SXn50G. The data replaces the defaults on the screen and fills in the unit details. v The program insists that you do this before allowing you to reprogram the unit to make it less likely that inappropriate values be entered.
To set the Rx Offset for the whole table, select Parameters > Rx Offset and pick from the list of possible values. 2.2.3.4 Programming Up To 80 Channels Individually Double-click the Tx Frequency value for the channel to program in the main frequency table, which brings up this dialog: Figure 15 - Frequency Programming Dialog v Valid values for the starting frequency are frequencies within the switching bandwidth which are multiples of the Comparison Frequency.
v This is only permitted if the Read from Unit command was previously used to upload settings at some point during the session. v If you did not do this, save the configuration to disk, read the unit, and then retrieve the configuration again. See below. 2.2.3.7 Completing Programming This completes programming and the unit may be disconnected. It is not necessary to switch off power or stop the program first. 2.2.3.
This can be achieved by any equipment with an RS232 serial port which can send the required byte. Only the TXD (to pin 9) and ground (to pin 5) connections are required. Figure 16 - Serial channel change connections (terminal pinout shown) v If you use a terminal, the equivalent keystrokes for channels 0 to 127 are listed in the appendix on page 36. 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
3 3.1 Part Three: Programming the Modem CHANGING MODEM PARAMETERS - WINSETGMSK v Modem parameters may be protected from change by a hardware link setting described on page 12. If you want to change modem parameters, they can be programmed by connecting a unit to a standard PC serial port and using a program, WinSetGMSK.exe, which you can download from the Wood & Douglas website, www.woodanddouglas.co.uk. It is also possible to program the modem using command sequences of serial bytes. See page 25.
3.1.3 Connecting Select the type of unit (e.g. RSX450) and the serial port to which it is connected (e.g. COM1). Try clicking the Auto Detect button to connect to the unit. If the connection fails, try manually selecting the speed and parity and clicking Connect. If the program tells you that the connection has failed, likely reasons are: v v v v 3.1.4 RSX unit not connected to serial port RSX unit not powered (or supply less than 9V for early units, see p.28) Adaptor not correctly wired (see p.
This tab allows you to read and set the values of parameters and control the modem, as follows. 3.1.4.1 Parameters Modem Parameter Range of Values Source address 0 to 255 This is the identity of the modem. It only accepts messages bearing this address as the destination, and adds it as the source address with all sent packets. Default is 10 Destination address 0 to 255 The identity of the intended recipient of a message.
3.1.4.2 Controls Command button Function Notes Reset Modem This command re-initialises the modem. Parameter settings are not affected. Set Factory Defaults Enter all default parameter settings and re-initialise the modem. You are asked to confirm. The default settings are as listed in this table. Save to EEPROM Save all parameters in EEPROM memory. If you save new communications parameters, you will have to reconnect using File > Connect.
Figure 19 - Terminal Mode 3.2.2 Telemetry Test This test sends a string which you type in (or the default string of a number and the date and time, if you leave the field blank) over the air, at intervals determined by the Delay field. Select the Telemetry Test tab, which automatically leaves command mode, fill in the details and click Start. The button legend changes to Stop: click it to end the test. Figure 20 - Telemetry Test mode 24 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
3.2.3 Closing WinSetGMSK To end the session with WinSetGMSK, click the X icon at the top right-hand corner of the window. If you have not saved changes to the modem parameters, you will be given the opportunity before the program closes. The unit returns to normal mode if it was in command mode. 3.3 CHANGING MODEM PARAMETERS USING SERIAL COMMANDS We recommend using the WinSetGMSK software as an easy and reliable method of programming modem features.
Modem Parameter or Command Command Byte Parameter byte Notes Mode of modem f 102 0, 1 or 2 Maximum frame length h 104 0 or 1 Transmitter start delay i 105 0 to 255 Units of 5ms. Default 2 = 10ms Transmitter stop delay j 106 0 to 255 Units of 0.5ms. Default 10 = 5ms Preamble msg length k 107 20 - 225 Length in bytes.
4 4.1 Part Four: Additional Information RANGE The following table gives an indication of the typical ranges to be expected between a transmitter and receiver that have simple end-fed dipole antennas.
4.2 VARIANT MODELS The RSX range of modems has been made in a number of variants. This manual is generally applicable to all of them, but there are some variations, of which the most important are listed below. In particular, earlier models require at least a 9V supply in order to function correctly. Later models with a wider supply range may always be substituted for earlier ones. To find out which model you have, refer to the label on the device and look for a model number of the form 01234 5678 A.
4.3 TIMING The modem system is “intelligent” and removes the need for the user to understand how the radio system operates in order to use the modem. The data to be transmitted is automatically stored while the transmitter is enabled A preamble sequence is then transmitted to ensure that the receive modem can synchronise to the incoming signal before the data is transmitted. The data is placed in HDLC packets with header and CRC information added.
4.4 TECHNICAL SPECIFICATIONS Frequency range : RSX150G 100 - 225MHz (banded, fixed at manufacture) RSX450G 400 - 470MHz (banded, fixed at manufacture) RSX850G 868 - 870MHz Usable band depends on frequency, please enquire. RF preset channels : 80 (selectable via separate RS232 serial input, frequencies programmable within band) Channel programming : Table of 256 equally-spaced frequencies with common Rx-Tx offset, or table of 80 individually-programmed frequencies and Rx-Tx offsets.
APPENDIX: 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 to the serial port of your equipment. 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 Further information and a downloadable manual can be found at www.easysync.co.uk/usbrs232_single.html.
APPENDIX: SXn50 RADIO PROGRAMMING SOFTWARE REFERENCE 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.
Select Rx Offset A number of choices, multiples of the Comparison Frequency, are offered. 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.
Help About Displays information about Wood & Douglas, including website and contact details. Check for GUI Update Checks the Wood & Douglas website for updates and offers to update your GUI if appropriate.
Minimum Frequency The minimum frequency refers to the transmit band, and is used by the software as a base-line for all other frequency information. The software will not allow a channel to be set to a frequency below this minimum (or, in the case of a received channel, this frequency plus the receive offset). This frequency is stored in the non-volatile EEPROM in the unit. 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
APPENDIX: 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.
Wood & Douglas Ltd, Lattice House Baughurst, Tadley, Hants, RG26 5LP Tel:+44 (0)118 981 1444 Fax: +44 (0)118 981 1567 email: sales@woodanddouglas.co.uk website: www.woodanddouglas.co.uk 1892 1139 - RSX Range of Intelligent Modems User Guide - v7.
