Adcon Telemetry A733 Revised technical manual and photos with schematics and bill of materials removed
ADCON
TELEMETRY
A733 RTU
Technical Reference (Type Approval)
SMART WIRELESS SOLUTIONS
ADCON
TELEMETRY
ADCON TELEMETRY AG
INKUSTRASSE 24
A-3400 KLOSTERNEUBURG
AUSTRIA
TEL: +43 (2243) 38 280-0
FAX: +43 (2243) 38 280-6
http://www.adcon.at
ADCON TELEMETRY INC
1001 YAMATO ROAD
SUITE #305, BOCA RATON
FL 33431 USA
TEL: +1 (561) 989-5309
FAX: +1 (561) 989-5310
http://www.adcon.com
ADCON TELEMETRY SRL
BD. ION IONESCU DELABRAD 8
R-71592 BUCHAREST
ROMANIA
TEL: +40 (1) 490-6083
FAX: +40 (1) 490-6086
http://www.adcon.ro
Proprietary Notice:
The Adcon logo, the A730 series, A720 series and addIT™, A733 series and
addWAVE, addVANTAGE and AgroExpert™ are trademarks or registered
trademarks 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 Telemetry AG. Disclosure to third parties of the information contained herein is prohibited. Neither the whole nor any part of the information contained in this
publication may be reproduced in any material form except with the prior written permission of Adcon Telemetry AG.
Release 1.0, December 14, 1999
Copyright ©1999 by Adcon Telemetry AG.
All rights reserved.
Table of Contents
Introduction ____________________________________________________7
About the A733 ______________________________________________________________ 7
Hardware _______________________________________________________9
Overview_____________________________________________________________________ 9
The Modem Interface _________________________________________________________________ 10
The Microcontroller and the Power Management Sections _________________________________ 10
The Analog + Digital I/O Interface Board ________________________________________________ 13
The Power Supply and the Serial Interface _______________________________________________ 13
External Power Supply_________________________________________________________________ 14
Specifications________________________________________________________________15
PCB Parts Placement (A733) __________________________________________________16
Bills of Materials _____________________________________________________________17
A733MB _____________________________________________________________________________ 17
A733CA _____________________________________________________________________________ 19
A733 Device’s Photographs___________________________________________________ 20
The A431 Radio Module _______________________________________ 25
About the A431 Radio Module________________________________________________25
Functional description________________________________________________________25
Receiver Section ______________________________________________________________________ 25
Transmitter Section____________________________________________________________________ 26
3
Manufacturing Issues ________________________________________________________ 28
Marking and labeling issues ____________________________________________________________ 28
Alignment Range and Switching Range __________________________________________________ 28
Tuning Procedure _____________________________________________________________________ 29
Setting Up the Default Parameters ______________________________________________________ 29
Commands valid for all bands ____________________________________________________ 30
Commands required for band 1 __________________________________________________ 30
Commands required for band 2 __________________________________________________ 30
Commands required for band 3 __________________________________________________ 30
Commands required for band 4 __________________________________________________ 30
Definitions ___________________________________________________________________________ 31
Test Equipment Settings _______________________________________________________________ 32
Network Analyzer (HP 8712 or equivalent)_____________________________________________ 32
Service Monitor (Rohde & Schwarz CMS50 or equivalent) _______________________________ 32
Trimming Elements____________________________________________________________________ 33
Adjusting the Receiver Front End _______________________________________________________ 33
Adjusting the VCOs ___________________________________________________________________ 34
Adjusting the Crystal Reference _________________________________________________________ 35
Checking the Receiver Parameters ______________________________________________________ 35
Checking the Transmitter Parameters ____________________________________________________ 35
Data Transfer Check ___________________________________________________________________ 36
PCB Parts Placement_________________________________________________________ 37
Bill of Materials (A431) _______________________________________________________ 38
Frequency Reference Specifications ___________________________________________ 42
A431 Module’s Photographs _________________________________________________ 43
Software ______________________________________________________45
Short Description____________________________________________________________ 45
Tasks _______________________________________________________________________ 45
Controlling the Unit__________________________________________________________ 47
Serial Communication Protocol _________________________________________________________ 47
General Format of a Command _________________________________________________________ 47
General Format of an Answer___________________________________________________________ 48
Commands___________________________________________________________________________ 48
CMDS _____________________________________________________ 48
TIME _____________________________________________________ 49
BL ____________________________________________________________________________ 49
FREQ _________________________________________________________________________ 49
DATA _________________________________________________________________________ 50
IMME _________________________________________________________________________ 52
4
INFO _________________________________________________________________________ 52
RX ___________________________________________________________________________ 53
TX ___________________________________________________________________________ 54
B ____________________________________________________________________________ 54
Returned errors list____________________________________________________________________ 54
Command line interpreter _______________________________________________________ 54
Device descriptors and storage handler ___________________________________________ 55
Real time clock ________________________________________________________________ 55
Radio interface ________________________________________________________________ 55
Notifications __________________________________________________________________ 55
Adcon Packet Radio Protocol _________________________________________________56
Digital Squelch _______________________________________________________________________ 56
Modulation Technique Used____________________________________________________________ 57
Generic Format of a Radio Frame _______________________________________________________ 57
Data Frames _________________________________________________________________________ 59
Frame Types _________________________________________________________________________ 59
Request ______________________________________________________________________ 59
Broadcast Answer ______________________________________________________________ 60
Broadcast Request _____________________________________________________________ 60
Ping __________________________________________________________________________ 61
Pong _________________________________________________________________________ 61
Fdev _________________________________________________________________________ 62
Data12 _______________________________________________________________________ 62
Set ID ________________________________________________________________________ 63
Set Slot Time and Sample Rate __________________________________________________ 64
Set Frequency _________________________________________________________________ 64
Set Battery Charge Levels _______________________________________________________ 65
General Acknowledge __________________________________________________________ 65
5
6
1. Introduction
1.1. About the A733
The A733 Remote Telemetry Unit (RTU) is a portable low-power, medium-range telemetry device capable of sampling up to 12 analog and 8 digital inputs (of which 4
are counter types); in addition, it can control up to 4 outputs. A 3-volt CMOS serial
interface is also built-in, allowing for configuration, data download, or expansion
(e.g. various bus implementations). 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 (12.5, 20 or 25
kHz channel spacing).
Due to its construction, as well as to the software controlling it, the power consumption is extremely low (average 1 mA—without sensors). The unit operates from a
built-in NiCd 6.2 Volt rechargeable battery, which is charged using either a solar
panel or an external power supply adapter. A special configuration may be implemented where no internal battery is used, rather the power is obtained exclusively
over an external connector.
The A733 is a ruggedized unit, complying with the IP65 environmental protection
class (NEMA 4). It can be easily installed and it integrates perfectly with an Adcon
A730 network.
This manual describes the technical details of the A733, both hardware and software. It is organized in several parts, as follows:
7
Introduction
• Hardware: includes the schematics as well as a description of the main board
and interface boards of the A733
• The A431 radio module: includes the schematics and description of the radio
module
• Software: a short description of the software with the most important commands that can be used to control the unit over the serial interface
This manual is intended for the radio approval authorities and laboratories.
8
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 25). The
main board (Figure 1) contains the radio unit, a low-speed modem interface, a microcontroller and a power management subsystem. For the analog inputs and the
digital inputs/outputs, two identical interface boards (A733CA) holding the 7-pin
Binder connectors are used. The serial line and the power are provided on a 5-pin
Binder connector, while the antenna is fed through a 50 Ω BNC connector.
Antenna
Figure 1.
A431 Radio
Module
3 V CMOS
Serial
Interface
A733 Block Diagram.
Digital I/O
Modem
Interface
µController
ADC
8
System Supply
12
Analog Inputs
External Power
Power
Management
Battery
9
Hardware
For further details, consult the schematic diagram in Figure 2.
2.1.1. The Modem Interface
The 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 (
thus the raw throughput varies between 1 and 2 kbps (average 1.5 kbps). The modem functions are essentially implemented in software. However, a signal conditioning is performed on both receive and transmit paths.
On receive, the buffered analog data signal from the radio unit is applied to a 3 kHz
low pass filter (U6). The filter output is further fed both to a Schmidt trigger (U5:A)
and a 100 Hz low-pass filter (U5:B), the output of the latter being used as a reference
for the slicer (the Schmidt trigger). The TTL data,
of the slicer (i.e. on TP1). The microcontroller overtakes the decoding operation (see
also “Modulation Technique Used” on page 57).
On transmit, a two-poles low-pass filter (U11) is used: its role is to “smooth” the
square signal
microprocessor-controlled, variable-gain amplifier built with U12/U13 is used to set
the modulation level for different bandwidths (12.5, 20 or 25 kHz). The selected value is stored in the microcontroller’s EEPROM during the aligning procedure.
TXDI
generated by the microcontroller. Before entering the filter, a
RXDO
, is obtained at the output
1/f
),
2.1.2. The Microcontroller and the Power Management Sections
The operation of the whole unit is under the control of U9, an Atmel ATMega 103
microcontroller. It is a powerful chip exhibiting a very low power consumption. Its
main functions are:
• Controls the radio unit
• Implements the modem functionality
• Assembles the radio frames and waits for requests from a remote
• Performs the sampling of the sensor inputs and the A/D conversion
• Stores the values in a local FIFO; manages the FIFO
• Implements the pulse counter function
• Manages the real-time clock
• Assures the power management
• 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.
10
The Microcontroller and the Power Management Sections
The radio unit is controlled via the SPI bus (to set the PLL chip parameters) and via
several ports of the microcontroller for such operations as transmit and receive. In
addition, the high current 5 volt LDO voltage source (U4) is switched on before the
radio module’s PA must be activated.The modem’s output (implemented in software) is available on PB5 (
TXDI
), while the receiver output is fed to PD4 (
RXDO
).
The A/D subsystem is used to sample the inputs (ADC0 to ADC5); the 6th and 7th
analog input are used for on-board measurements as local battery, internal temperature and
RSSI/PO
signal; the battery and temperature voltages are switched by
means of the analog switch U19. A stable 2.5 Volt reference supplied by U8 is applied to the A
pin. The reference is powered by the microcontroller only when
ref
sampling the A/D inputs. The external sensors are powered through U17. In order
to enlarge the maximum number of sensors sampled, several analog multiplexers
are used (U3/U7/U10). After sampling the A/D once, the software switches the multiplexers (using the signal
MUX
, pin PD2) and samples the inputs once again, thus
doubling to 12 the maximum number of analog inputs.
The sampled input values are stored in a FIFO memory based on a serial EEPROM
chip, U18. These values may be retrieved when a request is received over radio, or
over the serial line. The configuration parameters (e.g. the serial number of the device, the operating frequency, etc.) are stored in the microcontroller’s on-chip EEPROM.
The pulse counter functionality is implemented by means of the four interrupt inputs
INT4 to INT7 of the ATMega 103 microcontroller.
The power management supervises the charge/discharge of the battery (via Q1 and
half of U15), senses when it reaches the “misery” state and switches off the unit in
order to protect the battery (second half of U15). In addition, the software senses the
unit’s idle state (e.g. the unit is in a warehouse in storage condition), where no activities must be performed thus driving the unit into hibernation. If the unit is switched
off due to an extremely low battery level, Q2 would start it up again only if external
power is applied to the power connector (e.g. from a solar panel).
The terminal mode is implemented by means of the built-in UART. No on-board level drivers are present in order to minimize power consumption; a special adapter cable that performs the CMOS to RS232 level shift is available. By means of this cable
and using the implemented commands, various parameters can be changed/configured.
A brown-out supervisor chip (U14) is used to assure a smooth start-up of the microcontroller and avoid possible erratic behavior when the battery level descends below the minimum operating value (2.7 volts). The same chip activates the writeprotect signal of the serial EEPROM during reset, in order to protect the data in the
EEPROM.
11
The Analog + Digital I/O Interface Board
2.1.3. The Analog + Digital I/O Interface Board
The two identical interface boards ensure the connection between the main board
and the outside world (see Figure 3). The interface boards contain two connectors
each (
I/O A
and
I/O B
or
I/O C
and
I/O D
respectively) and some active/passive
components protecting the inputs. Each of the
I/O
connectors can accept:
• Three analog inputs
• One digital Input or Output (its function can be switched under program control, also remotely)
• One pulse counter input
Depending on the way R3 and R4 are populated, the power supply to the I/O devices can be either switched or permanent. This option is factory programmable
only. If R3 is populated, the power will be permanently applied to the sensors while
if R4 is populated, the power will be applied for a defined time (typically 2 seconds)
only shortly before the microcontroller samples the inputs.
2.1.4. The Power Supply and the Serial Interface
The
POWER
• External supply (battery or any DC source from
• External charge supply (either a solar panel or
• Communication over serial lines, at 19200 baud
connector allows for:
5.6 to 10 volts)
an AC adapter) if an internal rechargeable battery is used
Battery
Ext Power
5
4
3
Ground
RxD
1
2
TxD
Note: The serial line is 3 volt CMOS compatible, therefore a special adapter cable
must be used to reach the RS-232 levels. Also, if an external battery is used,
the internal battery must be disconnected.
13
External Power Supply
when the battery voltage drops below 5.6 Volts, and under 5.9 Volts the RF operation may stop.
POWER
I/O D
I/O C
I/O B
ANT
Figure 4.
I/O A
Connection of an external power supply.
2.2. Specifications
The A733 fulfills the specifications of the EN 300 220-1, Class 12, ETS 300 086 and
ETS 300 113, as well as the FCC Part 90.214 (Subpart J) of the CFR 47.
Note: The parameters below were measured with the A733 + A431 combination.
Parameter Min Typ Max Unit
Power Cable Serial Adapter Cable
Red
+
Black
-
+
RS232
+
5 to 10 Volt
Common
Supply 5.6 6.2 10.0 V
Operating Temperature -30 +70 °C
Relative Humidity 99 %
Class Protection IP65
Data Rate (Using the On-board Software Modem) 1000 1500
Operating Frequency (-44 version)
Operating Frequency (-46 version)
b
b
430 450 MHz
450 470 MHz
a
Frequency Stability (-20 to +50°C) ±1.5 kHz
Frequency Stability (-30 to +60°C) ±2.5 kHz
Receiver
Sensitivity (12 db S/S+N) -118 dBm
Image Frequency Attenuation (1st IF = 45 MHz) -70 dB
2000 bps
15
Hardware
Parameter Min Typ Max Unit
Local Oscillator Leakage 2 nW
Adjacent Channel Attenuation -70 dB
RSSI dynamic 90 dB
Operating Current (incl. On-board Microcontroller) 25 mA
Transmitter (all measurements made on a 50 Ω resistive load)
Output Power 27 dBm
Spurious Radiation 200 nW
Adjacent Channel Power (12.5 kHz version) -34 dBm
Adjacent Channel Power (25 kHz version) -44 dBm
Occupied Bandwidth (12.5 kHz version) 7.0 kHz
Occupied Bandwidth (25 kHz version) 12 kHz
Operating Current (incl. On-board Microcontroller) 600 mA
a. Data rate is content dependent.
b. This parameter represents the alignment range; the switching range can
be limited in the software to a narrower space (even to the extent of a
single channel).
2.3. PCB Parts Placement (A733)
Figure 5.
A733MB Parts placement (top).
16
A733CA
Figure 9.
Figure 10.
A733, Back view.
A733, Top view.
21
Hardware
Figure 11.
Figure 12.
A733, Bottom view.
A733, Left view.
22
A733CA
Figure 13.
Figure 14.
A733, Right view.
A733, Case opened.
23
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