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Internal Format Description (for the scope REC.RETRIEVEFRMT==0)

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Hi all,

I am trying to use the scope over telnet and for speed I am trying to use the "internal format" of the rec.retrivedata parameter, but I cannot find any complete description of what this internal format is.

My first guess is a grammar like ('F'N)?'-'?0xnnnnn

With the optional 'F' meaning floating point and the following N giving the 10^-N factor of the floating point, then the '-' to indicate a negative number and finally the main number nnnnn in hexadecimal.

I have not been able to observe many floating point numbers and I have actually only seen the F3 prefix. Wondering if the 3 will actually ever change and in which base it is written (hexadecimal?).

Thank you,

Leonard

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Leonard,
I have limited information on this, but this may answer your question.

REC.RETRIEVFRMT, can be set to be 0 or 1 – our scope is using 1 (internal format, high speed).

• The F indicates a scaling factor (optional)
• The number is given in hexadecimal

F3-0x56
• F3: scale is 1/(10^3)
• -: optional sign
• 0x56: => dec 86
• Value: - 86*scale = - 86/10^3 = -0.086

F30xA65
• F3: scale is 1/(10^3)
• no sign
• 0xA65: => dec 2661
• Value: 2661*scale = 2661/10^3 = 2.661

The scale factor is used to generate pseudo floats with 3 digits, this is why we have usually F3.
The scale factor is 1 digit (10^x).

The Integers will not have a factor:
-->REC.RETRIEVE
Recording
1000,1
IL.FB [Arms],VL.CMD [rpm],VL.FB [rpm],DIN1.STATE
F30x1,F30x0,F30x80,0x0

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Hi Leonard,

Your guess is correct. "F" = floating point, "3" = decimal places, "-" = negative value, "0x"= hex formating, all the following is the actual value.

Giving an example

0x1, F30x3193, F3-0x8A4

0, 12.691, -2.212

Couldn't find any occurrence where the floating point numbers have a difference to 3. To answer your actual question.

Regards,

Martin

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