User manual

Operator's Manual
920836 Rev A
81
Decoding Floating Point Numbers
Single precision values are held in four bytes. If these are arranged in decreasing value order we
get the following bits:
bit 31, bit 30, bit 29, bit 28 . . . . . bit 3, bit 2, bit 1, bit 0
NOTE: If the byte order command CORD is set for low byte first, the bytes as received in
a waveform descriptor are received in reverse order. However, within a byte the bits
keep their order, highest at the left, as expected.
From these bits we are to construct three numbers that are to be multiplied together: S X E X F
constructed as follows:
S = (-1)
s
E = 2
(e - 127)
F = 1 + f
S, E, and F are calculated directly from the 32 bits. The following diagram illustrates the
calculation of the vertical gain example: