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Analog Input is 2 bytes in size, with Data Resolution per bit of 0.01 Signed. what is the possible range of values for Analog input?

I am trying to understand this data format used for transporting data over a LPWAN....what is the range constraint of possible values for Analog Input and Output..

Type    IPSO    LPP     Hex     Data Size   Data Resolution per bit
Analog Input    3202    2   2   2   0.01 Signed
Analog Output   3203    3   3   2   0.01 Signed

https://github.com/myDevicesIoT/cayenne-docs/blob/master/docs/LORA.md

Jeryl Cook
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  • Is 0.01 a decimal or binary value? – BenjaminF Mar 06 '19 at 13:01
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    Hello, welcome to Math.SE ! You asked a question, but it is understandable in its present form. You should make the question as clear as possible. It is also very important to show what you have tried to answer the question before posting. – Tom-Tom Mar 06 '19 at 13:03
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    How is it possible to measure the size of an analog input in bytes? I would expect it to be measured in volts or amperes. I don't think you are asking about an analog input; perhaps you are asking about the output of the A2D converter and what original analog values it can represent. – David K Mar 06 '19 at 13:19
  • hello, thanks. i updated the question... – Jeryl Cook Mar 06 '19 at 20:27

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Here's a solution with a few assumptions.

The first assumption being that your number is stored in two's complement form. Most signed numbers are stored in two's complement form for various reasons. Unless you believe otherwise it's pretty safe to assume that's the format the analog to digital converter uses.

The second assumption is that the units are correct. 0.01 units of resolution per bit. The final answer seems strange so please provide additional information in the future.

To answer the first part of your question, your number is 2 bytes long, that's 16 bits. The range of a 16 bit two's complement number is from -32768 to 32767. Using 0.01 units to represent a single bit that gives you a range of -327.68 to 327.67.

Walter Gordy
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