Technical Manual
Table Of Contents
- Wireless Sensor Interface A720 (addIT™)
- 1. About the A720
- 2. Hardware
- 4. Software
- 4.1. AMOS
- 4.2. Mode Check
- 4.3. A/D Task
- 4.4. The Terminal Task
- 4.5. The Radio Interface Task
- 4.5.1. Digital Squelch
- 4.5.2. Modulation Technique Used
- 4.5.3. Generic Format of a Radio Frame
- 4.5.4. Data Frames
- 4.5.5. Frame Types
- 4.5.5.1. Request
- 4.5.5.2. Broadcast Answer
- 4.5.5.3. Set I/O Request
- 4.5.5.4. Read I/O Answer
- 4.5.5.5. Broadcast Request
- 4.5.5.6. Ping
- 4.5.5.7. Pong
- 4.5.5.8. Memory Dump Request
- 4.5.5.9. Memory Dump Answer
- 4.5.5.10. Data
- 4.5.5.11. Set ID
- 4.5.5.12. Set Slot Time and Sample Rate
- 4.5.5.13. Set Frequency
- 4.5.5.14. Set Battery Charge Levels
- 4.5.5.15. Set Pulse Counters Parameters
- 4.5.5.16. General Acknowledge
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Wireless Sensor Interface A720 (addIT™)
1. About the A720
The A720 Wireless Sensor Interface (also known as
addIT™
) is a low power, short
range telemetry device, capable of sampling up to 6 analog sensors and 4 digital in-
puts (of which 2 counter types); in addition, it can control two relays.
The frequency of operation is in the 432 to 470 MHz range, making it adaptable to
most radio communication regulations in the world. The output power is under 10
mW, while the modulation is narrow band FM (12.5 or 25 kHz channel spacing).
Due to its construction, as well as to the software controlling it, the power consump-
tion is extremely low (average 6 mW). The unit operates from a built in NiCd 6.2 Volt
rechargeable battery, which is charged either using an 600mW solar panel or an ex-
ternal 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 A720 is a ruggedized unit, complying with the IP65 environmental protection
class (NEMA 4). It can be easily installed and it integrates perfectly in an Adcon A730
system. Depending on the terrain, it assures a reliable wireless connection to an
A730MD or A730SD device to distances up to 800 meters, under favorable conditions
even more.