MO-270 manual
Contents
1. is the lock test result L for locked U for unlocked hhhh is an hexadecimal value corresponding to a status code see the User s Manual for error codes TSld lt cr gt Sets the modulator TS Input d decimal digit O ASI1 1 ASI2 2 TEST TSI cr TSld lt cr gt Asks for the current modulator TS input d as before Page 23 AXxPROMAX USER S MANUAL MO 270 Name Message Answer Description and Format MCRa lt cr gt Sets the modulator code rate d decimal digit 0 0 4 1 0 6 2 0 8 2MCR lt cr gt MCRak lt cr gt Asks for the current code rate as before MCO d lt cr gt Sets the modulator constellation d decimal digit 0 4QAM NR 1 4QAM 2 16QAM 3 32QAM 3 64QAM lt gt MCO d lt cr gt Asks for the current modulator constellation d as before FHLd lt cr gt Sets the modulator frame header length d decimal digit 0 420 1 595 2 945 2FHL lt cr gt FHLd lt cr gt Asks for the current modulator frame header length before lt gt Sets the modulator frame header phase d decimal digit O rotating 1 fixed 2FHP lt cr gt lt gt Asks for the current modulator frame header phase d as before TINd lt cr gt Sets the modulator time interleaving d decimal digit 0 240 1 720 TIN cr TINd lt cr gt Asks for the current time interleaving2. 270 DTMB MODULATOR pon Ax PROMAX SAFETY NOTES Read the user s manual before using the equipment mainly SAFETY RULES paragraph The symbol A on the equipment means SEE USER S MANUAL In this manual may also appear as a Caution or Warning symbol Warning and Caution statements may appear in this manual to avoid injury hazard or damage to this product or other property TABLE OF CONTENTS 1 GENERAL scrion soii 1 1 1 General description ER 1 2 Functional description sid 1 3 Specifications enceinte iret eret Leite Eee eet Ene ean 4 2 SAFETY RULES inane petiere pe m enki esu aee piena d aeneo p 2 1 General safety rules iss 2 2 Descriptive Examples of Over Voltage 8 3 INSTALLATION 9 3 1 BOST Supply 9 3 1 1 Operation using the Maina eeee sese eee eeeeeeee en 9 3 2 Installation and Startup arterat tartearen tr aar did 9 4 OPERATING INSTRUCTIONS erri 4 1 Front panel description 2 11 4 2 Rear panel description 12 4 3 Menu functions 13 4 4 MODULATOR functions 13 4 5 15 4 6 4 7 4 8 e 4 9 CONFIGURATION fUNCtiOnS rrun 19 AO TATU canas 20 4 11 REMOTE control through RS 232 interface 21 4 12 DTMB useful bit 2 27 4 13
3. Use for the signal inputs outputs specially when working with high levels appropriate low radiation cables Follow the cleaning instructions described in the Maintenance paragraph 01 2009 Page 7 AxPROMAX USER S MANUAL MO 270 Symbols related with safety DIRECT CURRENT ON Supply ALTERNATING CURRENT OFF Supply DIRECT AND ALTERNATING DOUBLE INSULATION Class II protection CAUTION Risk of electric shock GROUND TERMINAL PROTECTIVE CONDUCTOR CAUTION REFER TO MANUAL FRAME TERMINAL FUSE EQUIPOTENTIALITY 2 2 Descriptive Examples of Over Voltage Categories Cat Low voltage installations isolated from the mains Cat Il Portable domestic installations Cat Ill Fixed domestic installations Cat IV Industrial installations Page 8 01 2009 3 INSTALLATION 3 1 Power Supply The MO 270 is equipment powered through the mains for its operation 3 1 1 Operation using the Mains Connect the instrument to the mains through the AC voltage connector 12 located on the MO 270 rear panel Check if the mains voltage is according to the equipment specifications 3 2 Installation and Start up The MO 270 modulator is designed for use as a rack mounted 19 inches device 1U chassis Switch the main switch 13 located in the rear panel to position power on After a successfully start up the equipment emits four acoustic tones to indicate that it is ready to begin operation When the equip
4. d as before PlLd lt cr gt Sets the modulator pilots single carrier d decimal digit 0 OFF 1 ON PIL cr PlLd lt cr gt Asks for the current pilots state d as before lt gt Sets the modulator carrier mode d decimal digit 0 Multicarrier 1 Single Carrier lt gt CARd lt cr gt Asks for the current modulator carrier mode d as before INVd lt cr gt Sets the modulator spectral inversion mode d decimal digit O INV 1 NO INV 2INV lt cr gt INVd lt cr gt Asks for the current modulator spectral inversion mode d as before MODa lt cr gt Sets the modulator IF output mode d decimal digit 0 DTMB 1 TONE RMS MOD cr MODdecr gt Asks for the current modulator IF output mode d as before Page 24 01 2009 USER S MANUAL 270 AXPROMAX Name Message Answer Descriptionand Format FIFnn n lt cr gt Modify the equipment IF frequency nn n is the frequency value in Hz written with 8 digits from 31 to 37 MHz 2FIF lt cr gt FIFnn n lt cr gt Returns the current IF frequency in Hz and with 8 digits padding with 0 on the left DISd lt cr gt Disable the RF output d decimal digit O ENABLE RF 1 DISABLE RF DIS lt cr gt DISd lt cr gt Asks for the current RF disable state d as before MPR
5. 830 Hz in 0 1 Hz steps Note that depending on the output frequency in use 36 MHz IF or RF the same baseband Doppler frequency may correspond to different vehicle speeds The modulator is frequency agile The user can select an RF output frequency between 45 and 875 MHz in steps of 1 Hz In normal operation the IF output frequency is internally set by the modulator and varies between 31 and 36 MHz depending on the selected RF frequency The RF output can be switched off in which case the IF frequency is fixed at 36 MHz The polarity of the IF RF spectrum inverted or non inverted can be selected by the user The operation of the MO 270 is done via the front panel LCD display and controls The modulator can be easily configured by navigating through a rather intuitive set of menus A couple of LEDs located on the front panel signal the existence of errors in the modulator or whether the equipment is properly powered 01 2009 Page 3 AxPROMAX 1 3 Specifications A INPUTS MPEG 2 Transport Stream Operating modes IF OUTPUT Type Frequency range Spectrum polarity Power level average In band amplitude ripple In band group delay ripple Frequency stability MER RF OUTPUT Type Frequency range Spectrum polarity Power level average Frequency stability MER SSB phase noise DTMB PARAMETERS Carrier Mode Frame Header Length Frame Header Phase FEC rates Constellations Time Interleaving operation Pag
6. and validating selected options 01 2009 Page 11 ZXPROMAX USER S MANUAL MO 270 When the rotary encoder is pressed and we are modifying any equipment function the option currently being shown on the LCD panel is selected Turning the encoder clockwise CW or counter clockwise CCW allows us to navigate through each menu function and option available in the MO 270 4 2 Rear panel description The rear panel shows from right to left the mains socket for AC voltage input the fan air outlet a DB 9 connector for remote control via an RS 232C COM port two ASI inputs an IF nominally 36 MHz test output and the main RF output at the frequency and level chosen by the user RF E ASH Figure 2 Rear panel view 6 RF output 500 female N type connector 7 IE output 500 female BNC 8 ASH input 750 female BNC ASI input number 1 9 ASI2 input 750 female BNC ASI input number 2 10 RS 232C connector DB 9 DB 9 connector for remote control via an RS 232C COM port 11 AC voltage connector Supplies power to the equipment Includes the fuse 12 Mains switch Switch on or off the power supply NOTE The actual IF frequency value varies between 31 and 36 MHz depending on the RF frequency When a fixed 36 MHz is needed the RF output of the modulator has to be disabled in the RF menu Page 12 01 2009 4 3 Menu functions After start up the equipment display shows informat
7. 1 dB of flatness within the DTMB bandwidth 3 to 40 dB in 0 1 dB steps noise power varies whilst the DTMB signal power remains constant Fully digital complex baseband generation 6 echoes which may be switched on off individually Pure Doppler shift or constant phase 0 to 40 dBc in 0 1 dB steps O to 541 6 us in steps of 100 ns 8 MHz channels 830 to 830 Hz in 0 1 Hz steps 0 to 359 9 in 0 1 steps Generate a single carrier at the channel central frequency whose level equals the average DTMB output power This is intended for signal level alignment Internal generation of test TS using PRBS sequences of length 15 or 23 embedded within NULL packets Fully digital complex baseband generation Both signal noise can be switched off Flat within twice the bandwidth of the DTMB signal 1 dB of flatness within the DTMB bandwidth 3 to 40 dB in 0 1 dB steps noise power varies whilst the DTMB signal power remains constant Page 5 AXxPROMAX USER S MANUAL MO 270 ECHOES GENERATOR Amplitude From O down to 40 dBc in 0 1 steps Phase From 0 to 359 9 in 0 1 steps Doppler Static 0 Hz Dinamic from 830 Hz Delay Variable in 100 ns steps RS 232C INTERFACE POWER SUPPLY Voltage 90 250 VAC Frequency 50 60 Hz Consumption 20W OPERATING ENVIRONMENTAL CONDITIONS Indoor use Altitude Up to 2000 m Temperature range From 5 C to 40 C Max relative humidity 80 up to 31 C decreasi
8. 450000000 Hz 722000000 Hz 198500000 Hz 458000000 Hz 730000000 Hz 205500000 Hz 466000000 Hz 738000000 Hz 212500000 Hz 474000000 Hz 746000000 Hz 219500000 Hz 482000000 Hz 754000000 Hz 226500000 Hz 490000000 Hz 762000000 Hz 233500000 Hz 498000000 Hz 770000000 Hz 240500000 Hz 506000000 Hz 778000000 Hz 247500000 Hz 514000000 Hz 786000000 Hz 254500000 Hz 522000000 Hz 794000000 Hz 261500000 Hz 530000000 Hz 802000000 Hz 268500000 Hz 538000000 Hz 810000000 Hz 275500000 Hz 546000000 Hz 818000000 Hz 282500000 Hz 554000000 Hz 826000000 Hz 289500000 Hz 562000000 Hz 834000000 Hz 296500000 Hz 570000000 Hz 842000000 Hz 306000000 Hz 578000000 Hz 850000000 Hz 314000000 Hz 586000000 Hz 858000000 Hz 322000000 Hz 594000000 Hz 01 2009 AxPROMAX USER S MANUAL MO 270 OIRT channel plan 52500000 Hz 546000000 Hz 714000000 Hz 62000000 Hz 554000000 Hz 722000000 Hz 80000000 Hz 562000000 Hz 730000000 Hz 88000000 Hz 570000000 Hz 738000000 Hz 96000000 Hz 578000000 Hz 746000000 Hz 178000000 Hz 586000000 Hz 754000000 Hz 186000000 Hz 594000000 Hz 762000000 Hz 194000000 Hz 602000000 Hz 770000000 Hz 202000000 Hz 610000000 Hz 778000000 Hz 210000000 Hz 618000000 Hz 786000000 Hz 218000000 Hz 626000000 Hz 794000000 Hz 226000000 Hz 634000000 Hz 802000000 Hz 474000000 Hz 642000000 Hz 810000000 Hz 482000000 Hz 650000000 Hz 818000000 Hz 490000000 Hz 658000000 Hz 82600
9. Error Information 28 4 13 1 Types of errors 28 413 2 Error Coding ii errearen 29 5 MAINTENANCE 5 1 Mains fuse replacement is 5 2 Cleaning Recommendations sa 31 APPENDIX A Channel Plans AXxPROMAX USER S MANUAL MO 270 DTMB MODULATOR MO 270 1 GENERAL 1 1 General description The MO 270 is a DTMB modulator fully compliant with the standard GB20600 2006 The modulator input is an MPEG 2 transport stream TS in ASI format The outputs are DTMB signals up converted to IF and RF The MO 270 supports Single Carrier and Multicarrier modes and can be used in Multi Frequency Networks MFN Digital coding and modulation are implemented by means of programmable logic devices based on PROMAX own technology This makes the design highly flexible allowing it to tailor it to any particular application and offering plenty of features at low cost Highlights of this product are e Single Carrier and Multicarrier mode of operation High frequency resolution in steps of 1 Hz e High MER 1 2 Functional description The MO 270 is a general purpose DTMB modulator contained in a 19 1U chassis The unit has two serial MPEG 2 TS ASI inputs Either of these inputs can be used to modulate the DTMB signal An additional test TS can be generated internally in the modulator This allows generating compliant DTMB signals even in the absence of a valid TS input The
10. all possible combinations of FEC Rate and constellation values The payload data rate under a signal frame of 4200 symbols frame header length 420 symbols is shown on table 1 Signal Frame Length Signal frame 4200 symbols FEC Rate 0 6 4QAM NR 4QAM 8 122 16QAM 16 243 MAPING 32QAM 64QAM 24 365 Table 1 System Payload data Rate for 4200 symbols The payload data rate under a signal frame of 4375 symbols frame header length 595 symbols is shown on table 2 Signal Frame Signal frame 4375 symbols Length FEC Rate 0 6 0 8 4QAM NR 5 198 4QAM 7 797 10 396 16QAM 15 593 20 791 2 2 lt gt 2 25 989 64QAM 23 390 31 187 Table 2 System Payload data Rate for 4375 symbols The payload data rate under a signal frame of 4725 symbols frame header length 945 symbols is shown on table 3 01 2009 Page 27 AXxPROMAX USER S MANUAL MO 270 Signal Frame Length FEC Rate E 0 6 4QAM NR 4QAM 7 219 16QAM 14 438 32QAM 64QAM 21 658 Signal frame 4725 symbols 2 a lt gt Table 3 System Payload data Rate for 4725 symbols 4 13 Error Information When using the equipment operating errors can occur as well as errors related to the loss of synchronization in the MPEG 2 input transport stream The first 16 errors appearing during the i
11. of the IF RF spectrum inverted or non inverted can be selected by the user The MO 270 has been designed to work in Multi Frequency Networks Single Frequency Network SFN operation is not currently supported The MO 270 can add white Gaussian noise to the DTMB signal with a given Carrier to Noise Ratio C N This random noise is generated digitally and is available on both IF and RF outputs The noise bandwidth is more than twice the bandwidth of the DTMB signal The noise generator can be easily switched on and off When it is on the user can select the C N ratio The valid range is 3 to 40 dB in 0 1 dB steps Because both noise and signal are generated in the digital domain the accuracy of the so simulated C N ratio is very high The average power of the noise within the signal bandwidth can be easily measured at the output of the modulator by switching the useful signal off Menu entry Suppress Carrier NO YES Obviously the measured noise power will be approximately C N dB below the DTMB signal power Note that the DTMB signal power remains the same regardless of whether noise is added or not at the output The channel simulator implemented in the MO 270 allows the user to simulate both dynamic and static multipath scenarios Up to 6 echoes including the main path of variable amplitude delay phase and Doppler frequency can be selected The time varying complex baseband channel is simulated in the digital domain
12. rate only in single carrier mode OFF ON Spectral Inversion This function allows inversion of the spectrum generated in IF and As the IF spectrum is by itself inverted compared to the RF output the inversion applied is related to the RF output The possible options are OFF Carriers with lower indices occupy the lower frequencies of the RF channel ON Carriers with higher indices occupy the lower frequencies of the RF channel PRBS bits Selection of the length in bits of the internally generated pseudorandom sequences 23 PRBS sequences of length 223 1 15 PRBS sequences of length 225 1 4 5 RF functions The selection of this item allows us to access those functions related to the RF output Let s review each option Frequency This function allows the selection of the RF frequency Changes made by turning the rotary encoder are applied directly to the output allowing for a smooth tuning of the output frequency 01 2009 Page 15 ZXPROMAX USER S MANUAL MO 270 When entering this function the display shows the current frequency and the step used to modify it if the encoder is turned Frequency increments are positive when turning CW and negative if CCW The LCD panel looks as follows MENU back PUSH select TURN next prev RF Frequency 650000000 Hz lt 10MHz gt In this case the current output frequency is 650 MHz and turning CW one notch each notch is marked by an audible t
13. 0000 Hz 498000000 Hz 666000000 Hz 834000000 Hz 506000000 Hz 674000000 Hz 842000000 Hz 514000000 Hz 682000000 Hz 850000000 Hz 522000000 Hz 690000000 Hz 858000000 Hz 530000000 Hz 698000000 Hz 538000000 Hz 706000000 Hz UHF channel plan 474000000 Hz 610000000 Hz 746000000 Hz 482000000 Hz 618000000 Hz 754000000 Hz 490000000 Hz 626000000 Hz 762000000 Hz 498000000 Hz 634000000 Hz 770000000 Hz 506000000 Hz 642000000 Hz 778000000 Hz 514000000 Hz 650000000 Hz 786000000 Hz 522000000 Hz 658000000 Hz 794000000 Hz 530000000 Hz 666000000 Hz 802000000 Hz 538000000 Hz 674000000 Hz 810000000 Hz 546000000 Hz 682000000 Hz 818000000 Hz 554000000 Hz 690000000 Hz 826000000 Hz 562000000 Hz 698000000 Hz 834000000 Hz 570000000 Hz 706000000 Hz 842000000 Hz 578000000 Hz 714000000 Hz 850000000 Hz 586000000 Hz 722000000 Hz 858000000 Hz 594000000 Hz 730000000 Hz 602000000 Hz 738000000 Hz 01 2009 usemsmanuacmoro o APRAX STDL channel plan 50000000 Hz 482000000 Hz 674000000 Hz 58000000 Hz 490000000 Hz 682000000 Hz 62750000 Hz 498000000 Hz 690000000 Hz 66000000 Hz 506000000 Hz 698000000 Hz 178750000 Hz 514000000 Hz 706000000 Hz 186750000 Hz 522000000 Hz 714000000 Hz 194750000 Hz 530000000 Hz 722000000 Hz 202750000 Hz 538000000 Hz 730000000 Hz 210750000 Hz 546000000 Hz 738000000 Hz 218750000 Hz 554000000 Hz 746000000 Hz 226750000 Hz 56
14. 2000000 Hz 754000000 Hz 234750000 Hz 570000000 Hz 762000000 Hz 242750000 Hz 578000000 Hz 770000000 Hz 290750000 Hz 586000000 Hz 778000000 Hz 306000000 Hz 594000000 Hz 786000000 Hz 318000000 Hz 602000000 Hz 794000000 Hz 330000000 Hz 610000000 Hz 802000000 Hz 342000000 Hz 618000000 Hz 810000000 Hz 354000000 Hz 626000000 Hz 818000000 Hz 366000000 Hz 634000000 Hz 826000000 Hz 378000000 Hz 642000000 Hz 834000000 Hz 390000000 Hz 650000000 Hz 842000000 Hz 402000000 Hz 658000000 Hz 850000000 Hz 474000000 Hz 666000000 Hz 858000000 Hz 01 2009
15. 270 is able to work with any incoming bit rate as long as this is strictly lower than the value given in the DTMB specification for the modulation parameters in use See section 4 10 DTMB useful bit rates The input TS bit rate is adapted bit rate adaptation to the useful bit rate required by the DTMB signal by stuffing the TS with NULL packets packet stuffing This stuffing process alters the sequence of PCR values embedded in the TS These values have to be re stamped for the resultant PCR jitter to remain within the acceptable limits specified by the DTMB 01 2009 Page 1 AxPROMAX USER S MANUAL MO 270 Whenever possible it is advised to use an input bit rate considerably lower than the nominal value given in the DTMB specification Otherwise an input rate too close to the required value might eventually lead to overflow of the TS packet buffer implemented in the modulator The modulator can be configured to generate any of the transmission modes listed in the DTMB specification Several test modes are available in the MO 270 single tone output and test TS generation The modulator is frequency agile The user can select an RF output frequency between 45 and 875 MHz in steps of 1 Hz In normal operation the IF output frequency is internally set by the modulator and varies between 31 and 36 MHz depending on the selected RF frequency The RF output can be switched off in which case the IF frequency is fixed at 36 MHz The polarity
16. able attenuator of 60 dB in 1 dB steps At the same time the nominal RF level can be finely adjusted using a voltage controlled attenuator This allows to set a reference level using the voltage controlled attenuator to then apply the mentioned 1 dB attenuation steps to that reference value That RF gain structure can be controlled using the following functions Attenuation this function allows to select the RF output level by applying 1 dB attenuation steps from O dB to 60 dB Turning the encoder CW increases the attenuation reducing the output level Turning CCW enables the opposite behaviour Level changes are applied immediately to the RF output to allow smooth and easy adjustment of RF output conditions Pressing the encoder or MENU key exits this function e Fine Adjust Select this function to program the RF output reference level For a correct reference adjust the output attenuation to O dB before the fine adjustment Changes are also applied in real time Turning the knob CW increases the output level Turn it CCW decreases the level The displayed characters are integer numbers The range goes from a maximum attenuation of 31 to a minimum attenuation of 31 i e O to 63 attenuation steps To exit this function press the MENU or encoder keys 4 7 NOISE This menu item collects the functions related to the digitally synthesized white noise Generator Turns the noise generator ON OFF C N Selects a C N ratio va
17. according to the following equation h t pele as SA n 2 Page 2 01 2009 Echoes 2 to 6 have amplitude p constant phase hu delay t and pure Doppler frequency fp Echo number 1 has amplitude p constant phase and Doppler frequency bu lts delay is assumed O and therefore it is taken as the time base reference for all the other echoes When fon 0 for all n the channel does not vary in time and h t t h t This is the channel used to characterise fixed or roof top reception It s usually nonetheless useful to add some Doppler 1 or 2 Hz to a static channel in order to slowly stir its phase For echo number 1 6 its amplitude p is computed using the following formula where A is the amplitude of echo number n referred to the echo of maximum amplitude of the channel and expressed in dBc valid range is 0 dBc down to 40 dBc in 0 1 dB steps Note that the echo of maximum amplitude is not necessarily the first echo as happens for instance when pre echoes are present in the channel The above formula normalises the channel so that the total power of the DTMB signal sum of echoes remains equal to the nominal DTMB signal power when no echoes are present The range of echo delays goes from O to 541 6 us and can be incremented in steps of 0 1 us for each of the six echoes The echo phase is fixed ranging between 0 and 359 9 in 0 1 steps The Doppler frequency has a valid range of 830 Hz to
18. d lt cr gt PRBS of 15 or 23 bits d decimal digit 0 15 bits PRBS 1 23 bits PRBS lt gt MPRd lt cr gt Asks for the current PRBS length with d as before MREd lt cr gt PCR restamping master mode ON OFF d decimal digit 0 ON 1 OFF MRE lt cr gt MREd lt cr gt Asks for the current restamping state d as before MPL cr MPLdad cr Asks for the TS packet length detected ASCII text 188 or 204 bytes NOld lt cr gt Sets the noise generator ON OFF d decimal digit 0 OFF 1 ON 2NOl lt cr gt NOld cr Asks for the noise generator state d as before CNRddd lt cr gt Sets the C N value in dB x 10 ddd decimal digits value between 030 and 400 3 0dB to 40 0dB CNR cr CNRddd cr Asks for the current C N value ddd as before SIGd lt cr gt Sets the signal generator ON OFF d decimal digit 0 ON 1 OFF SIG lt cr gt SIGd lt cr gt Asks for the signal generator state d as before ECOd lt cr gt Sets the echoes generator ON OFF d decimal digit 0 OFF 1 ON ECO lt cr gt 01 2009 ECOd cr Asks for the signal generator state d as before Page 25 ZXPROMAX USER S MANUAL MO 270 Name Message Answer Descriptionand Format EAMdaaaa lt cr gt Sets the amplitude of t
19. e 4 USER S MANUAL MO 270 Two ASI inputs 75 female BNC TS packets of length 188 or 204 bytes automatic detection Support for burst and continuous packet mode Input TS bit rate strictly below the value given in the DTMB specification Packet stuffing for bit rate adaptation and PCR re stamping are carried out automatically 50 BNC female connector Variable between 31 and 36 MHz in steps of 1 Hz fixed at 36 MHz when output is off Selectable via front panel controls 0 dBm 107 dBuV fixed lt 0 5 dB lt 10 ns 20 ppm gt 43 dB 50 Q N type female connector Adjustable between 45 and 875 MHz in 1 Hz steps Selectable via front panel controls Approximately 80 dBuV with no attenuation Variable attenuation of O to 60 dB in steps of 1 dB 20 ppm 38 dB 87 dBc Hz O 2 kHz Single Multicarrier 420 595 945 symbols Fixed Rotating 0 4 0 6 0 8 4QAM NR 4QAM 16QAM 32QAM 64QAM 240 720 Available 01 2009 USER S MANUAL 270 NOISE GENERATOR Characteristics Bandwidth C N CHANNEL SIMULATOR Characteristics Number of taps Profiles Amplitudes Delays Doppler Phase TEST MODES Single carrier R M S Tone TS packet generation NOISE GENERATOR Characteristics Bandwidth C N 01 2009 AXPROMAX Fully digital complex baseband generation Both signal and or noise can be switched off Flat within twice the bandwidth of the DTMB signal
20. e and place afresh the fuseholder Fuse 5x20 2A T 250V THE BREACH OF THESE INSTRUCTIONS COULD DAMAGE THE EQUIPMENT 5 2 Cleaning Recommendations CAUTION To clean the cover take care the instrument is disconnected CAUTION Do not use scented hydrocarbons or chlorized solvents Such products may attack the materials used in the construction of the cover The cover should be cleaned by means of a light solution of detergent and water applied with a soft cloth Dry thoroughly before using the system again CAUTION Do not use for the cleaning of the front panel alcohol or its derivatives These products can attack the mechanical properties of the materials and diminish their useful time of life 01 2009 Page 31 AXxPROMAX USER S MANUAL MO 270 Page 32 01 2009 usersmanua moze o APRAX APPENDIX A Channel Plans CCIR channel plan 50500000 Hz 330000000 Hz 602000000 Hz 57500000 Hz 338000000 Hz 610000000 Hz 64500000 Hz 346000000 Hz 618000000 Hz 107500000 Hz 354000000 Hz 626000000 Hz 114500000 Hz 362000000 Hz 634000000 Hz 121500000 Hz 370000000 Hz 642000000 Hz 128500000 Hz 378000000 Hz 650000000 Hz 135500000 Hz 386000000 Hz 658000000 Hz 142500000 Hz 394000000 Hz 666000000 Hz 149500000 Hz 402000000 Hz 674000000 Hz 156500000 Hz 410000000 Hz 682000000 Hz 163500000 Hz 418000000 Hz 690000000 Hz 170500000 Hz 426000000 Hz 698000000 Hz 177500000 Hz 434000000 Hz 706000000 Hz 184500000 Hz 442000000 Hz 714000000 Hz 191500000 Hz
21. en included at the end of this document see Appendix A The selections displayed using the rotary encoder are CCIR Main west European standard STD L French standard OIRT East European standard UHF Only the UHF part from CCIR for faster selection 01 2009 Page 19 ZXPROMAX USER S MANUAL MO 270 IF Mode By using this function the user can select generating a DTMB signal or a single tone A single tone can be useful for accurate alignment or testing of external components The available options are DTMB Generate a DTMB signal TONE RMS Generate a single tone at an RMS level equal to the RMS level of the modulated DTMB signal 4 10 STATUS These functions provide information about errors software and firmware versions Error List During the continuous operation of the MO 270 the first 16 errors detected are stored as a reference to identify problems Usually no errors are generated and the display should be as follows MENU back PUSH select TURN next prev NO ERRORS But during operation two different kinds of errors are possible See section 4 11 Error information Errors generated when the modulator is not locked to the selected TS input These are usually temporary errors related to input transport stream transitions or invalid TS bit rates Errors generated due to a circuit failure When this kind of errors persists the instrument must be serviced in a PROMAX official c
22. enter See section 4 11 for an explanation of the format used to display the errors e Clear Errors select this function to clear the internal error counter and errors list explained formerly The possible selections are NO YES e Firmware Indicates the version firmware included in the equipment A sample Screen looks as follows MENU back PUSH select TURN next prev CONFIGURATION Firmware v1 0 02 84 00 Page 20 01 2009 4 11 REMOTE control through RS 232 interface The MO 270 has an RS 232C compatible serial port to connect to a computer for remote control A suitable set of remote control commands allows enquiring and changing any functional parameter Communication details There is a control protocol to synchronize command reception and validation A command must be sent once an XON coded 0x11 hexadecimal value 11 or 17 in decimal character is received from the instrument When the instrument detects a complete command it sends an XOFF 0x13 code and once validated and executed an ACK 0x06 or NAK 0x15 code is sent to the remote controller To ensure error free communication between the two devices the communication parameters for the serial port on the remote controller are as follows Rate 115200 bauds Data bits 8 bits Parity None Stop bits 1 The MO 270 accepts remote commands at any time when the instrument is on Its not necessary to put the instrument in a special remote control mode The com
23. he echo d aaaa decimal digits selects the echo value between 0 and 5 a amplitude value in dBc x 10 lt gt EAMaaaa lt gt Asks for the amplitude of the echo d and a as before EPHdpppp lt cr gt Sets the phase of the echo d pppp decimal digits d selects the echo value between 0 and 5 p phase value in degrees x 10 2 EPHd lt cr gt EPHpppp cr Asks for the phase of the echo d and p as before EDOdsffff lt cr gt Sets the Doppler frequency shift of the echo d s ffff decimal digits selects the echo value between 0 and 5 S sign of the sift f frequency value in Hz x 10 value between 830 0Hz to 830 0Hz lt gt EDOSffff cr Asks for the Doppler frequency shift of the echo d s and T as before EDLdtttt lt cr gt Sets the delay of the the echo d tttt decimal digits d selects the echo value between 0 and 5 t delay value in ps x 10 EDLd lt cr gt EDLtttt cr Asks for the delay of the echo d and T as before STE lt cr gt Saves the current configuration of echoes and C N RCE lt cr gt Retrieves the current configuration of echoes and C N saved before Page 26 01 2009 AXPROMAX USER S MANUAL MO 270 4 12 DTMB useful bit rates At the following tables you can see the useful bit rates Mbits s or Mbps for
24. ion regarding the main operating conditions as can be seen in the following example FREQ 474000000 Hz ATT 0 dB CM MC CONST 64QAM 945 TI 720 Here the RF frequency is 650 MHz the 1 dB step RF attenuator is set to 10 dB the DTMB signal is in multicarrier mode uses a 64 QAM constellation a frame header length of 945 symbols and time interleaving of 720 symbols After a few seconds the display changes its contents to show the working time and error count information as follows MO 270 PROMAX ELECTRONICA S A Working 01 13 55 ERR 0 The text on the upper line the name of the company in the example above could be customised via the RS232 port to the user s needs allowing for an easy identification of the equipment or for some piece of advice Pressing the MENU key allows us to enter the main menu level Pressing MENU again takes us to the main status display This main menu level uses the first text line to give some advice on the operation assigned to each control and the second line to display the selectable options and functions MENU back PUSH select TURN next prev MODULATOR Turning the encoder CW or CCW cycles through the submenu titles MODULATOR RF LEVEL TEST CONFIGURATION d M oct 4 4 MODULATOR functions At this menu level the modulator parameters can be modified and customised to the user s needs When modifying any modulation parameter changes became active only when confir
25. lue from 3 to 40 dB in 0 1 dB steps Suppress Carrier Turns ON OFF the COFDM signal to which the white Gaussian noise is added 01 2009 Page 17 AXxPROMAX USER S MANUAL MO 270 4 8 ECHOES This menu contains a series of parameters to be defined in order to simulate terrestrial transmission channels Generator Turns the channel simulator ON OFF ECHO 1 Sets the parameters for the first channel tap Reference Echo This tap exhibits zero delay and is taken as the reference of the time base for all the other echoes Note that its amplitude is not necessarily O dBc This allows to define channels with preechoes i e channel profiles whose tap of maximum amplitude is not the first one Press the encoder key to access the first echo parameters definition Amplitude Turns this tap ON OFF or sets its amplitude level from 0 down to 40 dBc in 0 1 dB steps Phase Tap phase from 0 to 359 9 in 0 1 steps Doppler Doppler shift frequency to define static O Hz or dynamic from x 830 Hz taps ECHO n Defines the settings for each channel tap referred to the echo set as reference Amplitude Turns this tap ON OFF or sets its amplitude level from 0 down to 40 dBc in 0 1 dB steps Phase Tap phase from 0 to 359 9 in 0 1 steps Doppler Doppler shift frequency to define static O Hz or dynamic from x 830 Hz taps Delay Depending on the channel BW this is the echo delay referred to echo 1 and variable in 100 ns step
26. med by pressing the encoder function Instead pressing the MENU key allows us to cancel the change of option Let s comment on each function 01 2009 Page 13 AxPROMAX USER S MANUAL MO 270 TS Input Selects the input used for providing a Transport Stream TS to the COFDM modulator Options are ASI1 Use TS provided at ASI1 input connector rear panel ASI2 Use TS provided at ASI2 input connector rear panel PRBS Use internally generated PRBS data to generate TS test packets FEC Rate Using this function the user can modify the LDPC code rate for the Transport Stream TS The available options are as follows 0 4 0 6 0 8 Constellation Here the menu allows the selection of one of the available constellations The options are 4QAM NR 4QAM IGOAN 32QAM 64QAM Frame Header Length This function selects the required frame header length for the signal The available values are 420 symbols 595 symbols 945 symbols Frame Header Phase In this function the rotation of the frame header phase can be selected for PN identification purposes The options are Fixed Rotating only for 420 and 945 frame header length Page 14 01 2009 Time Interleaving There are two options for the time interleaving 240 symbols 720 symbols e Carrier Mode The modulator has these options Single Carrier MultiCarrier e Pilots Insert two pilots at 0 5 symbol
27. ment is connected to the mains the green LED LINE 3 remains lit 01 2009 Page 9 AXxPROMAX USER S MANUAL MO 270 Page 10 01 2009 4 OPERATING INSTRUCTIONS WARNING The following described functions could be modified based on software updates of the equipment carried out after manufacturing and the publication of this manual 4 1 Front panel description JAL PROMAX MO 270 DTMB MODULATOR MO 278 DTMB Modulator vi 1 08 p a c 2099 PROMAX Electronica SA Es 0 Figure 1 Front panel 1 LCD display With 2x40 characters crisply clear due to its white LED backlight 2 ERROR RED LED has a couple of functions For each operating second the first tenth of that second indicates whether there are sync problems in the modulator ON or not OFF Examples are loss of TS sync or invalid input bit rates The remaining nine tenths of a second the RED LED shows whether errors lasting more than 5 seconds since the last time the error counter was cleared are detected ON 3 LINE A GREEN LED indicator shows when the power supply is ON 4 MENU The MENU key allows the user to enter and exit the menu functions and to modify the equipment functional parameters modulation parameters output frequency and level and other configuration and setup functions 5 Rotary encoder button This has many different functions Moving across the different display menus and sub menus
28. munication is carried out using the transmitter and receiver data lines on the serial port Also the control signals CTS and RTS must be connected A standard PC computer DB9F to DB9F NULL MODEM serial cable can be used when connecting the instrument to an available COM port The communication protocol is as follows 1 MO 270 transmits a XON code 0x11 every second The aim is to indicate to any possible remote device that the equipment is ready to receive data 2 At this moment data streams can be sent to it Each data stream is made of Initial character code 0x2A Set of characters that describe data message Final character CR carry return code OxOD 3 Once a data stream has been sent an XOFF will be received indicating that the transmission of any new command must wait until completion of the current one 4 Next if the message format is correct and its execution has no errors an ACK acknowledge should be expected Otherwise an NAK not acknowledge will be received 5 If the sent message requires an answer it will be sent at this point 01 2009 Page 21 ZXPROMAX USER S MANUAL MO 270 6 Once completed the message processing the MO 270 will send an XON indicating that its ready for a new command A typical communication timing diagram would be as follows MO 270 equipment ready for command command issued by the controller command received indication 1 2 NA lt cr gt g
29. n USRtext lt cr gt Set a new USER text to be displayed in the LCD panel text is an ASCII text with a maximum of 32 characters 2USR lt cr gt USRtext lt cr gt Returns the current USER text STOnn lt cr gt Save the current configuration to a memory nn is a decimal value from 00 to 11 RCLnn lt cr gt Retrieve a configuration from a memory nn is a decimal value from 00 to 11 FRQnn n lt cr gt Modify the equipment RF frequency nn n is the frequency value in Hz written with 9 digits from 45 to 875 MHz 2FRQ lt cr gt FRQnn n lt cr gt Returns the current RF frequency in Hz and with 9 digits padding with 0 on the left lt gt Change the RF output attenuation nn is the new decimal attenuation value in dB lt gt lt gt Returns the current attenuation value nn value using 2 decimal digits padding with 0 on the left 2ERN lt cr gt ERNnn n cr Retrieve the internal error counter nn n value using 8 decimal digits padding with 0 on the left ERC lt cr gt Clear the internal error counter 2ERLnn lt cr gt ERLtext lt cr gt Retrieve an error message nr is the error index in decimal value text is the text string in ASCII format LOK cr LCKehhhh lt cr gt Retrieve the locked status
30. n this type of errors occur the MO 270 presents an error message on the LCD display starting with the word STATUS and followed by an explanation of the type of error e g TS SYNC LOST TS BUFFER FULL or INVALID TS RATE Needless to say in this scenario the ERROR LED flashes red for 5 seconds and then stays lit until the error count is cleared within the CONFIGURATION menu The numerical fields have the following meaning XX Hexadecimal value composed by several information bits with meaning according to the modulator configuration Eight bits compose the data structure Each bit marks an error status when its value is 1 except when the opposite is indicated b7 b6 b5 b4 b3 b2 b1 b0 Bits b7 b6 b4 b2 and b1 are always 0 b5 TS buffer full The input TS bit rate is above the maximum value You must reduce the transpor stream bit rate b3 TS sync lost The synchronisation with the input TS has been lost The most probable cause is that an input transport stream is not available or that is has been temporally disconnected bO It is always 1 YY This complementary information is also expressed in hexadecimal The value of each bit indicates a possible anomaly in the operation of the circuit In all cases a deviation with respect to the value of reference indicates a failure in some of the circuits that compose the modulator Contact technical assistance CSC for repair The value of reference all OK is 1B which corres
31. ng lineally up to 50 at 40 C MECHANICAL FEATURES Dimensions 19 W x 1 75 H x 15 D Weight 6 3 kg RECOMMENDATIONS ABOUT THE PACKING It is recommended to keep all the packing material in order to return the equipment if necessary to the Technical Service Page 6 01 2009 2 SAFETY RULES A 2 1 General safety rules The safety could not be assured if the instructions for use are not closely followed Use this equipment connected only to systems with their negative of measurement connected to ground potential This is a class 1 equipment for safety reasons plug it to a supply line with the corresponding ground terminal This equipment can be used in Overvoltage Category Il installations and Pollution Degree 1 environments When using some of the following accessories use only the specified ones to ensure safety Power cord CA005 Observe all specified ratings both of supply and measurement Remember that voltages higher than 70 V DC or 33 V AC rms are dangerous Use this instrument under the specified environmental conditions The user is only authorized to carry out the following maintenance operations Replace the fuses of the specified type and value On the Maintenance paragraph the proper instructions are given Any other change on the equipment should be carried out by qualified personnel The negative of measurement is at ground potential Do not obstruct the ventilation system of the instrument
32. nstrument operation are internally registered and can be retrieved or erased by means of the functions in CONFIGURATION menu This section describes the error list display format and the meaning of the codes that appear in each case for each type of error 4 13 1 Types of errors The control program of the MO 270 can detect and show up to 4 types of errors Some of them correspond to instrument malfunction and must be directly reported to a PROMAX s Customers Service Centre CSC Others state incorrect options about modulator input signals 1 An internal device connected to control IC bus does not respond to the messages from the microcontroller It requires service of CSC 2 UNKN Unknown error Due to a problem different to the one previously described the 1 C control system cannot be accessed It requires service of CSC 3 BUSY The 2 bus controller is busy and has not been possible to recover its operation It requires service of CSC 4 MOD FAIL It covers all errors corresponding to the MPEG 2 transport stream inputs not being correctly synchronized and or not having the right bit rate Page 28 01 2009 4 13 2 Error Coding BUSY and UNKN are for internal use of Promax If any of these errors occurs repeatedly the equipment ought to be taken to a PROMAX s customer service centre for repair MOD FAIL The display format for this type of errors is as follows ERRO2 MOD FAIL STATUS XXYY CCC C Whe
33. one will change that value to 660 MHz In this situation each time we press the encoder button the frequency step will be modified to 1 MHz 100 kHz 10 kHz 1 kHz 100 Hz 10 Hz 1 Hz and again to 10 MHz allowing a cyclic selection of the desired step value To quit this function the MENU key must be pressed e Channel Using the set of channel tables included in the MO 270 makes the output frequency tuning faster This allows direct selection of standard frequencies used in most countries Entering this function a list of all available channels is displayed sequentially Turning the encoder will lead us to the desired one Pushing the encoder selection key will exit that function The channel list is taken from a set of channel plans loaded into the equipment The available channel plans are displayed and selected from the CONFIGURATION menu as we ll see later Also in this case frequency changes are applied immediately to the RF stage allowing an interactive frequency adjustment The list of channel plans can be found in Appendix A Disable This option is to disable the RF output This is performed by introducing a strong attenuation around 80 dB to the RF signal At the same time the IF frequency is tuned to a nominal value of 36 MHz The selectable values are NO YES Page 16 01 2009 4 6 LEVEL functions This menu item collects the functions related to RF level adjustment The MO 270 has a built in programm
34. ponds to the following value of each bit HEX b7 b6 b5 b4 b3 b2 b1 bO 1B 0 0 0 1 1 0 1 1 01 2009 Page 29 AxPROMAX USER S MANUAL MO 270 Bits b7 and b6 are always 0 Bit b1 is always 1 A change in bits b5 b4 or b3 indicates failure in the IF generation circuitry Digital to Analogue converter A change in bits b2 or bO implies failure in the DTMB modulator circuitry CCC This parameter is a global error counter It counts the number of errors at the moment in which the error message is displayed Therefore if an error of any type occurs continuously this counter will have a different value whenever we look at some of the first 16 errors detected by the equipment In relation to this value it must be noted that in order to detect an error for example the loss of synchronization with a TS input the equipment waits for this situation to occur for more than 5 seconds So it avoids errors in the transitions between different modulator functions or temporary TS input disconnections to be counted However the total error counter CCC C counts each occurrence regardless of whether or not it lasts more than 5 seconds Page 30 01 2009 5 MAINTENANCE AS 5 1 Mains fuse replacement The fuseholder is located on the back panel of the equipment Before replacing the fuse disconnect the mains cord Take out the fuse holder with screwdriver Replace the fuse damaged by a suitable new on
35. s Page 18 01 2009 4 9 CONFIGURATION functions Under this menu tree there is a collection of functions related to the configuration and setup of the whole instrument Save to Memory The MO 270 has a number of configuration memories that allow to store the modulator parameters as well as the RF frequency and level To store the current configuration turn the encoder to select the desired memory number from O to 10 Press the encoder key to confirm the storing action Press the MENU key to cancel the action This function as well as the recall option explained hereafter automatically increments the memory number to allow to easily store and recall the contents of consecutive memories Load from Memory This is the counterpart function of the previous one Selecting the desired memory number a complete equipment configuration can be loaded Save C N 8 Echoes The MO 270 stores in memory the parameters related to C N amp Echoes previously defined Turn the encoder to select the desired option Press the encoder key to confirm the storing action Press the MENU key to cancel the action Load C N 8 Echoes Allows to load the previously stored settings Channel Plan Use this function to choose among the channel plans included in the MO 270 Currently the available channel plans an ordered list of channel frequencies have been translated from the standard analogue channel plans A complete list of all channel plans has be
36. t 3 XOFF 5 wait execution delay 6 NAMO 270 lt cr gt command answer sent 7 wait usually some small delay 8 equipment ready for command 4 command accepted understood All characters are transmitted in ASCII code Commands should always be sent in capital letter and cannot be edited online i e once a character is received it is stored in the MO 270 buffer and cannot be rectified by sending an erase code When in communication idle mode MO 270 waiting for a command the instrument will send an XON code at one second intervals to allow synchronization Command list Commands are classified between interrogative and control commands They are initiated by sending an character and have ASCII text format and always share a similar structure For instance the equipment model name can be asked by sending NA lt cr gt and the answer is NAMO 270 always without quotes Some amount of parsing must be applied to recover the wanted data from the answer text in this case MO 270 Here follows a table with all available commands Page 22 01 2009 USER S MANUAL 270 2NAM lt cr gt 9 NAMMO 270 lt cr gt AXPROMAX Name Message Answer Description and Format Retrieve equipment model 2VER lt cr gt gt VERVO 7 10 lt cr gt Retrieve SW version BEP lt cr gt Acoustic indicatio
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