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ADC

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T E L E M E T R Y

 

SMART WIRELESS SOLUTIONS

 

A440 Wireless Modem

 

Technical Reference Manual

Summary of Contents for A440

Page 1: ...ADCON T E L E M E T R Y SMART WIRELESS SOLUTIONS A440 Wireless Modem Technical Reference Manual ...

Page 2: ...e The Adcon logo the A730 series A720 series and addIT A440 and add WAVE addVANTAGE and AgroExpert are trademarks or registered trade marks of Adcon Telemetry AG All other registered names used throughout this publication are trademarks of their respective owners This publication contains confidential information property of Adcon Teleme try AG Disclosure to third parties of the information contai...

Page 3: ...________________________13 PCB Parts Placement A440 __________________________________________________15 Bills of Materials _____________________________________________________________15 A440MB _____________________________________________________________________________ 16 A440 Device s Photographs___________________________________________________21 The A431 Radio Module _______________________...

Page 4: ...____________________________________________ 37 Data Transfer Check ___________________________________________________________________ 38 PCB Parts Placement_________________________________________________________ 39 Bill of Materials A431 _______________________________________________________ 41 Frequency Reference Specifications ___________________________________________ 45 A431 Module s Pho...

Page 5: ...__________________________________________________ 57 Radio interface ________________________________________________________________ 57 Notifications __________________________________________________________________ 57 Adcon Packet Radio Protocol _________________________________________________57 Digital Squelch _______________________________________________________________________ 58 Modulat...

Page 6: ...6 ...

Page 7: ...e 1 mA The unit operates from an extrenal 5 6 to 10 volt power supply The power is fed via the common data power connector cable The A440 is a ruggedized unit complying with the IP65 environmental protection class NEMA 4 It can be easily installed and is compatible with both the standard Adcon low speed protocol and the upcoming high speed protocol This manual describes the technical details of th...

Page 8: ...8 Introduction This manual is intended for the radio approval authorities and laboratories ...

Page 9: ...ce a microcontroller RS 485 and RS 232 interfaces and a power conditioning subsystem The power and the serial lines are provided over a corresponding con nector 4 pin Binder for RS 485 or D sub 9 pin for RS 232 while the antenna is fed through a 50 Ω TNC connector Figure 1 A440 Block Diagram A431 Radio Antenna µController Modem Interface Power Conditioning System Supply Power Module Low Speed Mode...

Page 10: ...a On transmit the low speed data is generated again by the slave microcontroller U5 added by the R 2R network implementing a D A converter The slave microcontrol ler generates in effect the sinus waveforms required to encode the binary data The output signal is applied to the audio mixer U11 which adds the signal generated by the high speed modem U7 Obviously only one modem will be activated at a ...

Page 11: ...stem is used to sample the RSSI and Pout inputs A stable 2 5 Volt reference supplied by U3 is applied to the Aref pin The reference is powered by the microcontroller only when sampling the A D input The serial interface is implemented by means of the built in UART Both the RS 232 and RS 485 interfaces are implemented using Maxim chips U12 and U17 respective ly The serial interface mode is selected...

Page 12: ...Supply In order to test the unit over the specified supply range a special power cable is sup plied by Adcon Telemetry This cable must be connected to the interface connector of the unit before the serial cable see Figure 3 The two wires with banana plugs may then be connected to an external variable power supply the red plug to plus and the black plug to minus WARNING Do not apply more than 10 Vo...

Page 13: ...o a narrower space even to the extent of a single channel 430 450 MHz Operating Frequency 46 version b 450 470 MHz Frequency Stability 20 to 50 C 1 5 kHz Frequency Stability 30 to 60 C 2 5 kHz Receive mode Sensitivity 12 db S S N 118 dBm Image Frequency Attenuation 1st IF 45 MHz 70 dB Local Oscillator Leakage 2 nW Adjacent Channel Attenuation 12 5 kHz mode 57 dB RSSI dynamic 90 dB Operating Curren...

Page 14: ...re 6 A440 Front view 55 1 XTAL MC306 32 76KH z MC 306 X1 Seiko Epson 56 SMD Header 1 SLY8 SMD 055 4 S 2mm J1 Fischer Elektronik 57 Jumper 1 CAB10 2mm to J1 Fischer Elektronik Pos Description Count Component Name Value Pattern Ref Des Manufacturer ...

Page 15: ...22 Hardware Figure 7 A440 Back view ...

Page 16: ...23 A440MB Figure 8 A440 Top view Figure 9 A440 Bottom view ...

Page 17: ...24 Hardware Figure 10 A440 Left and Right views ...

Page 18: ...25 A440MB Figure 11 A440 Case opened Figure 12 A440 Motherboard top view ...

Page 19: ...26 Hardware Figure 13 A440 Motherboard bottom view ...

Page 20: ...g The power con sumption in receive mode is remarkably low under 32 mA in spite of the good IP3 characteristics and high sensitivity The switching from receive to transmit is fast un der 20 mS 3 2 Functional description The following functional description refers to the schematic diagram in Figure 14 3 2 1 Receiver Section The antenna signal is fed through the common low pass filter for both recei...

Page 21: ...el signal is ob tained on pin 18 of U8 and is fed to switch U6 As long as the module is in receive mode the RSSI signal will be present on the RSSI PO pin of the interface connector 3 2 2 Transmitter Section The carrier is generated directly on the operating frequency by means of the VCO built around U2 The signal is locked on the reference OSC1 with the aid of the dual PLL chip based on U9 The ch...

Page 22: ...he same time the same modulation signal is applied to the inverting op amp U4 and then to the OSC1 reference oscil lator a VCTCXO The modulation signal is inverted in order to bring it in phase with the VCO modulation point 3 3 Manufacturing Issues 3 3 1 Marking and labeling issues The A431 Module is manufactured in two versions Low band able to operate between 430 and 450 MHz High band able to op...

Page 23: ...0 MHz Note The boards differ only through the FL1 and FL2 in that Band 1 and 2 use models TOKO 493S 1071A and 492S 1056A while Band 3 and 4 use models TOKO 493S 1075A and 492S 1060A respectively In addition the tuning pro cedure and some software parameters differ The differences are clearly stat ed in the following paragraphs where applicable Note Special versions could also be delivered having s...

Page 24: ...Commands required for band 2 SR 440000000 450000000 BL 440000000 450000000 FREQ 445000000 12500 Commands required for band 3 SR 450000000 460000000 BL 450000000 460000000 FREQ 455000000 12500 Commands required for band 4 SR 460000000 470000000 BL 460000000 470000000 FREQ 465000000 12500 Note The SR command sets the switching range limits the BL command sets the band limits and the FREQ command set...

Page 25: ... relevant signals from the module to their cor responding test cables The directional coupler connects the antenna input output of the device under test to both the network analyzer and the service monitor The schematic diagram of the testing fixture is depicted in Figure 16 Figure 16 Schematic Diagram of the Testing Fixture 0 765 V Out Scope Ant I O Out Voltmeter Out Network Analyzer Testing Fixt...

Page 26: ...1 435 MHz Mkr2 430 MHz Mkr3 440 MHz band 2 Mkr1 445 MHz Mkr2 440 MHz Mkr3 450 MHz band 3 Mkr1 455 MHz Mkr2 450 MHz Mkr3 460 MHz band 4 Mkr1 465 MHz Mkr2 460 MHz Mkr3 470 MHz Note It is a good idea to store the instrument state for the four settings for a rapid recall when needed 3 3 6 2 Service Monitor Rohde Schwarz CMS50 or equivalent The setting for the receiver section check are as follows RX T...

Page 27: ...e host via the serial cable 2 Select the appropriate instrument profile depending on the device s band 3 Turn the DUT in permanent receive mode by entering the RX command at the terminal 4 Adjust the FL1 and FL2 filters see Figure 17 until you obtain a curve similar to the one shown in Figure 18 depending on the band the markers may be different this is done by successively adjusting the five trim...

Page 28: ...e shown on the voltmeter is again 1400 mV 50 mV 5 Press the enter key at the terminal to switch the unit off Note A one time calibration of the Testing Fixture may be needed due to the in ternal resistance of the voltmeter and the serial resistor mounted on the Test ing Fixture The calibration is performed by measuring the VCO voltage directly on the TP2 and by comparing the value with that measur...

Page 29: ...several seconds you will see the image on the scope pulsing at about one second intervals 5 Switch the RF generator output off 6 Verify that the RSSI threshold is correct by typing the command RSSI the actual value must be lower than the threshold set If this is not the case repeat the RSSI command several times perhaps the frequency is in use a radio receiver set on the operating frequency would ...

Page 30: ...mote station model A733 must be installed and operated on the same test frequency in the near vicinity no more than 30 m Note The base or remote station used for this test must be operated with a fictive antenna a 50Ω resistor To perform the test enter the command B at the terminal prompt the base and or remote station must answer with the RF in and out values If an answer is not re ceived after s...

Page 31: ...45 Data Transfer Check 3 6 Frequency Reference Specifications ...

Page 32: ...46 The A431 Radio Module 3 7 A431 Module s Photographs Figure 21 A431 Module General view Figure 22 A431 Module Top view ...

Page 33: ...47 Data Transfer Check Figure 23 A431 Module Bottom view ...

Page 34: ...48 The A431 Radio Module ...

Page 35: ...ck RTC Task The system usually remains in sleep mode Each 0 5 seconds an interrupt is gener ated by the local 32 76 Khz crystal oscillator This wakes up the processor and acti vates the CMX RTOS which allows all active tasks to perform their functions After all the tasks have finished their jobs CMX brings the system back to sleep The 0 5 seconds interrupt routine is also used as time reference fo...

Page 36: ...aracter 4 3 2 General Format of a Command The commands have the following format ID Command Param1 Param2 ParamN ID is the destination device If you include an ID as part of a command the node checks whether ID ownID If it does the node executes the command on itself If the ID is not the node s ID the node executes the command on a remote device if such an ID exists If the ID is missing this impli...

Page 37: ...he line may be ignored ErrResult shows whether the command was successfully executed If this value is 0 the command was successfully executed If this value is other than 0 the command failed The number may further indicate the error type See also Returned errors list on page 56 The answer string may contain any number of spaces or CR LF characters between its components however after the terminato...

Page 38: ...he actual frequency band limits in Hz REMARKS GET SET This is a hidden command i e not available for the normal user in the CMDS list REMOTE No EXAMPLE SR 432000000 450000000 193 SR 0 BL 193 SR 432000000 450000000 0 BL DESCRIPTION Sets returns the band limits PARAMETERS The frequency band limits Hz or none in the GET version RETURNS The actual frequency band limits in Hz REMARKS GET SET This is a ...

Page 39: ...the local device RETURNS A data block REMARKS GET only If the date time parameter is not included the latest data is returned If the date time parameter is included the date and time closest to but later than the given date time is returned REMOTE Yes for a GET but only one frame at a time The A440 implements only the remote version EXAMPLE DATA 193 12 12 1998 12 12 12 193 DATA b1 b2 b3 bn 0 The d...

Page 40: ...O rf_in rf_out date time ver clk stack cop batt temp days_uptime hr min_uptime rssi pmp_low pmp_high type slot samples err_level The formats for the above parameters are as follows rf_in and rf_out as a decimal unsigned char date as dd mm yyyy time as hh mm ss ver as x x clk stack and cop as decimal unsigned char they represent internal housekeeping parameters the A440 uses cop to number watchdog ...

Page 41: ... for A733 5 for A723 6 for A440 slot and samples are the actual values programmed by means of the SLOT command err_level is the error value 0 means no error REMARKS GET only REMOTE Yes GET only The A440 can issue the command both remotely and locally EXAMPLE INFO 193 INFO 255 0 18 4 1999 21 5 11 1 3 0 0 0 91 72 40 1 46 58 65 72 3 900 15 0 RX DESCRIPTION Switches the unit to permanent receive mode ...

Page 42: ... TX 0 TX 1 193 TX 0 TX 5 193 TX 0 B DESCRIPTION Sends a broadcast frame PARAMETERS None RETURNS A data block REMARKS After the device sends the broadcast frame it will listen for answers All valid an swers will be listed with their IDs REMOTE No EXAMPLE B 193 B 0 234 BA 0 7851 BA 0 4 3 5 Returned errors list Following are error messages you might get Command line interpreter 1 nonexistent command ...

Page 43: ...nal error 18 attempt to insert a reserved device ID number 0 or 65535 Real time clock 20 incorrect time supplied no conversion to time_t was possible Radio interface 30 error at receive CRC etc 31 unexpected frame received 32 wrong length 33 reserved 34 reserved 35 time out remote device not responding 36 receiver busy for example just making the request round Notifications 40 request to read a no...

Page 44: ...dure takes under 20 mS typically from wake up to result If however an RF level superior to the preset threshold is detected the micropro cessor will try to detect a valid header which is composed of a 2 kHz tone of at least 0 5 seconds long The tone detection is performed by the microcontroller in soft ware and takes at most 6 additional milliseconds If no valid tone is detected the unit goes back...

Page 45: ... transmitted as a 500 µs one level followed by a 500 µs zero level A complete sequence of one and zero level forms a bit cell This modulation scheme is self clocked The transmission speed is content depen dent varying from 1 kbps when sending only ones to 2 kbps when sending only zeros On the average an 1500 bps transmission speed is reached The data interchange between stations is made by means o...

Page 46: ... passed to the upper layer of the soft ware The data frames recognized by the A440 and their answers are detailed in Data Frames on page 61 A device will answer to the requesting device with the answer frame The answering device will poll the radio channel for an acknowledge the acknowledge may be ei ther the same frame send further up the network if the communication has hops i e routing stations...

Page 47: ...in the diagram TYPE is the type of frame HLEN is the header length it represents the number of bytes used to de scribe the route the frame will go or went The maximum number of hops is 8 that is 8 intermediate stations plus source and destination Each station is described by its unique 16 bit address SRC HOP and DEST are the source the hops and the destination addresses While the hops may be missi...

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