Fluke 2635A, User Manual

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Appendices
Binary Upload of Logged Data
C
C-5
just the most significant mantissa bit, so the raw binary byte stream value is 7f c0 00 00
(hex).
For all other measurement queries, Hydra Series II usually returns ±1e9 for overload
(OL) measurement values. However, for the LOG_BIN? query, Hydra Series II returns
Inf (infinity) instead. The IEEE floating point standard defines Inf as a positive or
negative maximum exponent number with a zero mantissa. Hydra Series II rInf
as the byte stream 7f 80 00 00 (hex) and -Inf as ff 80 00 00 (hex).
Table C-1. Floating-Point Format
Sign
1 bit
Exponent
8 bits
Manitssa
23 bits (plus one hidden bit)
high byte
(MMSB)
High-mid byte
(MLSB)
low-mid bute
(LMSB)
low byte
(LLSB)
The C code in Figure C-2 converts raw data into a useful format for the Intel x86 (IBM
PC) architecture. The BCD time stamp is converted to integers, and floating point
numbers created for the totalizer and measurement values.