ADCON T E L E M E T R Y A440 Wireless Modem Technical Reference Manual SMART WIRELESS SOLUTIONS
ADCON T E L E M E T R Y A D C O N T E L E M E T RY A G INKUSTRASSE 24 A-3400 KLOSTERNEUBURG A U S T R I A TEL: +43 (2243) 38 280-0 FAX: +43 (2243) 38 280-6 h t t p : / / w w w. a d c o n . a t ADCON TELEMETRY INC 1 0 0 1 YA M A T O R O A D SUITE #305, BOCA RATON F L 3 3 4 3 1 U S A TEL: +1 (561) 989-5309 FAX: +1 (561) 989-5310 h t t p : / / w w w. a d c o n . c o m A D C O N T E L E M E T RY S R L BD.
Table of Contents Introduction ____________________________________________________7 About the A440 ______________________________________________________________ 7 Hardware _______________________________________________________9 Overview_____________________________________________________________________ 9 The Modem Interfaces ________________________________________________________________ 10 The Microcontroller and the Power Conditioning Sections _________________________________ 10 The Power Supply
Alignment Range and Switching Range __________________________________________________ 30 Tuning Procedure _____________________________________________________________________ 31 Setting Up the Default Parameters ______________________________________________________ 31 Commands valid for all bands ____________________________________________________ 32 Commands required for band 1 __________________________________________________ 32 Commands required for band 2 ___________________________________________
TX ___________________________________________________________________________ 55 B ____________________________________________________________________________ 56 Returned errors list____________________________________________________________________ 56 Command line interpreter _______________________________________________________ 56 Device descriptors and storage handler ___________________________________________ 57 Real time clock ________________________________________________________________ 57 Ra
1. Introduction 1.1. About the A440 The A440 Wireless Modem is a portable low-power, medium-range serial interface telemetry modem. The unit is based on a powerful 8-bit Flash RISC microcontroller, which can also be programmed in the field (for software upgrades). The units incorporates an A431 radio module operating in the 430 to 470 MHz range, making it adaptable to most radio communication regulations in the world. The output power is 0.5 W, while the modulation is narrow band FM (12.
Introduction This manual is intended for the radio approval authorities and laboratories.
2. Hardware 2.1. Overview Most of the electronics (including the A431 radio module) are situated on the main board (for the A431 description, see “The A431 Radio Module” on page 27). The main board (Figure 1) contains the radio unit, a low-speed and a high speed modem interface, a microcontroller, RS-485 and RS-232 interfaces and a power conditioning subsystem.
Hardware For further details, consult the schematic diagram in Figure 2. 2.1.1. The Modem Interfaces The low speed modem operates with two tones: 1 kHz (representing the “1” bits) and 2 kHz (representing the “0” bits). A bit cell is represented by a complete time period (1/f), thus the raw throughput varies between 1 and 2 kbps (average 1.5 kbps). The modem functions are essentially implemented in software by a separate microprocessor.
The Microcontroller and the Power Conditioning Sections • Implements a serial Command Line Interface (CLI) The chip operates at its maximum speed, in this case 4 MHz (the “L” version), and uses a crystal (X2) for the on-board clock generator. The real time clock is implemented by means of a 32.768 kHz crystal (X1) connected on the internal Timer/ Counter0.
The Power Supply and Serial Interface 2.1.3. The Power Supply and Serial Interface The interface connector allows for: • External supply (any DC source from 5.6 to 10 volts) • Communication over serial lines, at 19200 baud (RS-485). 2 1 3 4 Gnd V+ B A For testing purposes, Adcon supplies a 220VAC power adapter that provides also an RS-485 to RS-232 conversion. Thus, the unit can be connected to a serial port of a PC and can be switched in various operating modes.
Hardware Note: The parameters below were measured with the A440 + A431 combination. Parameter Min. Typ. Max. Unit Supply 5.6 6.2 10.0 V Operating Temperature -30 +70 °C 99 % 2000 bps Common Relative Humidity Class Protection RF Data Rate (Using the low-speed Modem) IP65 1000 RF Data Rate (Using the high-speed Modem) 1500a 8000 bps Operating Frequency (-44 version)b 430 450 MHz Operating Frequency (-46 version)b 450 470 MHz Frequency Stability (-20 to +50°C) ±1.
A440MB Pos Description Count Component Name Value Pattern Ref Des Manufacturer 1 XTAL-MC306 32.76KH z MC-306 X1 Seiko Epson 55 56 SMD Header 1 SLY8/SMD/055/4 S 2mm J1 Fischer Elektronik 57 Jumper 1 CAB10 2mm to J1 Fischer Elektronik 2.5. A440 Device’s Photographs Figure 6. A440, Front view.
Hardware Figure 7. 22 A440, Back view.
A440MB Figure 8. A440, Top view. Figure 9. A440, Bottom view.
Hardware Figure 10. A440, Left and Right views.
A440MB Figure 11. A440, Case opened. Figure 12. A440 Motherboard, top view.
Hardware Figure 13. A440 Motherboard, bottom view.
3. The A431 Radio Module 3.1. About the A431 Radio Module The A431 was specially designed for narrow-band FM data communication. It exhibits a relatively flat response in the audio band from 10 Hz to 2.5 kHz, both on send as well as on receive paths. Additionally, the receiver’s group delay is very low. The module operates in the 430 to 470 MHz range, making it compatible with most radio communication regulations in the world. The output power is 0.5 W, while the modulation is narrow-band FM (12.
The A431 Radio Module The incoming signal is then applied to the first mixer, U7, through an LC impedance matching network (L12/C48). The local oscillator signal is obtained by means of the VCO built around U10 and applied to the mixer (the LO has a lower frequency than the incoming signal). The VCO is locked to the OSC1 reference by means of the U9 dual-PLL chip.
The A431 Radio Module An Automatic Level Control (ALC) system is responsible for keeping the output power constant, regardless of the external influences (temperature, VCO excitation and/ or supply). A small part of the RF energy is rectified by D2 and applied to the U5:A amplifier. By means of U5:B, the power is controlled according to the pre-set power level (ALC input). U5:A is basically an analog comparator between the actual and the programmed power output.
Tuning Procedure Consequently, two test reports will be provided to Adcon Telemetry AG. For North America (FCC), only the portion 460 to 470 MHz will be used; therefore, a single device model A440-46 having the switching range between 460 and 470 MHz will be submitted for testing. 3.3.3. Tuning Procedure The A431 modules are to be tuned by mounting them on a test fixture consisting of a specially modified A733 motherboard (the A733 is an universal low cost Remote Telemetry Unit manufactured by Adcon).
The A431 Radio Module # prompt should appear on the terminal screen (nnnn is the actual ID of the unit that is printed on its label).
Definitions 3.3.5. Definitions The diagram of the setup environment is depicted in Figure 15. Scope Service Monitor Network Analyzer Voltmeter 0.765 V Optional Directional Coupler Out Scope Ant I/O Out Out Voltmeter Network Analyzer RS232 To/From PC A733MB Connector Testing Fixture + 6.5 V – Figure 15. Trimming Setup. The testing fixture is used to fasten the A431 Module under test both mechanically and electrically in such a way as to allow its rapid and comfortable alignment.
The A431 Radio Module 3.3.6. Test Equipment Settings Before proceeding, certain controls on the test equipment must be set; some of the settings depend of the operating band (high or low) of the device under test (DUT). In addition, it is highly recommended that the ambient temperature during alignment is kept to 22° C (±1°C). 3.3.6.1. Network Analyzer (HP 8712 or equivalent) The settings for the Network Analyzer are as follows: • Center frequency: 450 MHz • Span: 100 MHz • Display: 10.
Trimming Elements 3.3.7. Trimming Elements The location of the trimming elements on the A431 Module is shown in Figure 17. FL2 FL1 L15 (RX VCO) L7 (TX VCO) R75 (Crystal Reference) Figure 17. Location of the trimming elements. 3.3.8. Adjusting the Receiver Front End 1. Mount the DUT (Device Under Test) on the testing fixture and connect it to the host via the serial cable. 2. Select the appropriate instrument profile depending on the device’s band. 3.
The A431 Radio Module If the adjustments do not achieve the appropriate curve, check the power supply, the cable connections to/from the test equipment, etc. Verify also that all the pins of the FL1 and FL2 filters are properly soldered. Figure 18. Helical Filter + LNA’s selectivity diagram. 3.3.9. Adjusting the VCOs 1. Verify that the DUT is in receive mode (enter the RX command at the terminal program). 2.
Adjusting the Crystal Reference • No parts are missing, or have the incorrect value, or are badly soldered (check the parts around U2 and U10). 3.3.10. Adjusting the Crystal Reference 1. Switch the unit to transmit mode by entering TX at the terminal. 2. Observe the indication shown by the Service Monitor: adjust R75 (see Figure 17) until the carrier frequency indicates 435000000 (Band 1), 445000000 (Band 2), 455000000 (Band 3), or 465000000 MHz (Band 4) ± 200 Hz, respectively. 3.3.11.
The A431 Radio Module c. Frequency Deviation: ±1.5 kHz (±0.2 kHz) 3. Switch the unit to stand-by by pressing the Enter key. For item 3.a above, adjust R75 (see Figure 17). For item 3.b, issue the command PWR at the terminal and use the D (down) and U (up) keys until the required value is reached. Finally, for item 3.c, issue the command BW at the terminal and again use the D and U keys to reach the required value. 3.3.13. Data Transfer Check The last check is a radio data transfer.
Data Transfer Check 3.6.
The A431 Radio Module 3.7. A431 Module’s Photographs Figure 21. A431 Module, General view. Figure 22. A431 Module, Top view.
Data Transfer Check Figure 23. A431 Module, Bottom view.
The A431 Radio Module 48
4. Software 4.1. Short Description The software is written entirely in C. It consists of a collection of standard C library functions, a preemptive multitasking operating system (CMX) offering basic configuration and administration functions (including a command line terminal on a serial port), and the application software itself, which assures the desired functionality of the device. 4.2.
Software 4.3. Controlling the Unit The unit under test can be controlled by means of the special adapter box A720PS that supplies the unit on one hand, and performs the RS-485 to RS-232 signal conversion on another hand. The serial output of the box can be connected to a PC (e.g. a laptop) by means of a null modem cable. In order to switch the unit to various modes of operations, a simple communications terminal program will suffice (e.g. Terminal or Hyperterminal in Windows, or tip/cu under Unix).
General Format of an Answer 4.3.3. General Format of an Answer The answers have the following format: ID Command Result1 Result2 ... ResultN ErrResult # • ID is the answering device. If a command was further routed, it is the ID of the end device. The answer must always contain the ID on return. • Command is the string representing the original command.
Software PARAMETERS The actual time, or none in the GET version. RETURNS The actual time as dd/mm/yyyy hh:mm:ss. REMARKS GET/SET. REMOTE No. EXAMPLES TIME 12/12/1999 22:10:10 193 TIME 0 # TIME 193 TIME 12/12/1998 22:10:10 0 # SR DESCRIPTION Sets/returns the band switching limits. PARAMETERS The switching band limits (Hz), or none in the GET version. RETURNS The actual frequency band limits, in Hz. REMARKS GET/SET. This is a hidden command (i.e.
Commands FREQ DESCRIPTION Sets/returns the operating frequency. PARAMETERS The operating frequency and step (Hz), or none in the GET version. RETURNS The actual frequency and step, in Hz. REMARKS GET/SET. REMOTE Yes, SET only. EXAMPLE FREQ 433925000 25000 193 FREQ 0 # FREQ 193 FREQ 433925000 25000 0 # DATA DESCRIPTION Returns data stored for a certain device. PARAMETER The ID of the device for which the data is requested and the date/time (in the standard format) the data was stored.
Software • cs is a 16-bit checksum obtained by summing the bytes and discarding the carries over 0xFFFF The remote version is limited to a single frame. An example of such a command is given below: 9999 DATA 9999 30/9/1999 14:50:00 9999 DATA 30 9 1999 14 54 55 21 37 255 255 77 0 0 0 0 89 156 126 20 0 0 0 0 0 0 0 0 0 3197 0 # Notice that if you need to get data that is not the last (newest) slot remotely from a device, the ID must be supplied twice.
Commands • days_uptime in days; together with hr:min_uptime, it represents the amount of time the device is up without a reset or watchdog • hr:min_uptime in hours:minutes format • rssi as decimal (unsigned chars); it is the programmed value with the RSSI command • pmp_low and pmp_high are the programmed values with the PMP command • type is used to represent the device type; following types are assigned currently: — 0 for A730MD — 1 for A720 — 2 for A730SD — 3 for A720B — 4 for A733 — 5 for A723 — 6 for A4
Software PARAMETERS None (sends an unmodulated carrier), 1 (sends a 1 kHz modulated carrier), 0 (sends a 2 kHz modulated carrier) or 5 (sends a mixed 1 + 2 kHz modulated carrier). RETURNS Nothing. REMARKS The system stops, and exits the command only when a key is pressed. This command returns no message. REMOTE No. EXAMPLE TX 193 TX 0 # TX 1 193 TX 0 # TX 5 193 TX 0 # B DESCRIPTION Sends a broadcast frame. PARAMETERS None. RETURNS A data block.
Returned errors list • 6 — operation not implemented Device descriptors and storage handler • 10 — device not found (attempt to perform a command on a nonexistent device) • 11 — device already exists • 12 — reserved • 13 — no more space for descriptors (too many devices) • 14 — no more records for the specified device • 15 — temporary communication break, no more data (the last request was not successful) • 16 — time-out (the handler blocked or is busy) • 17 — internal error • 18 — attempt to insert a reser
Software AA440. In addition, full source routing of frames for other destinations is implemented. Timeout Expired le Ac k e l N ew ic nt Tw Fr am igna No S e Se Idle Fram Po s se sib c 0.5 Wait Nhops + 1 s and Hunt Syncs rupt Measure RF Inter De er No Ack M ad Resend Frame with Long Header called We are Payloa d is for us Ack Get Frame No He Check Destination rou Ack Not for us tec ted e te t us Update Header and Send Answer Appropriately Figure 24.
Modulation Technique Used (low speed modem) to sleep. The destination ID is positioned very early in the frame header (see also “Generic Format of a Radio Frame” on page 59). From the above it becomes clear that in order to initiate a communication, a requester must send first a header which is at least 0.5 seconds long: these are called long header frames. Of course, after the communication is established the headers are short, of only 16 bytes (i.e. 8 msec. – called short header frames).
Software • After the header, a synchronization character is used; this is a hex 0xAA byte. The implementation must ensure that a 16-bit sync character is checked, i.e. 0x00AA, and not only an 8-bit 0xAA character. • Following the synchronization pattern, the bytes are assembled by shifting the bits one by one: each 8 contiguous bits will be “cut” into a byte.
Data Frames 4.4.4. Data Frames The data frames (payload) are the blocks of data extracted from the radio frames, after the CRC and other information (source address) was checked. The data frame and its length are passed to the upper layers of the software. TYPE HLEN SRC-H SRC-L HOP1-H HOP1-L ....... HOPn-H HOPn-L DEST-H DEST-L DATA1 DATA2 Header (Frame Type + Routing Information) ....... DATAn Data Figure 25. Generic Data Frame structure.
