Michell Instruments Promet EExd User Manual page 74

APPENDIX F
Examples of floating point to HEX are shown below.
1) +10.3
sign bit = 0
Exponent = 3, therefore exponent field = 127 + 3 = 130, and bits 30 to 23 = 10000010
Mantissa = 1.2875 which in binary representation = 1 .01001001 1001 1001 1001 101
Adjusting the mantissa for the exponent moves the decimal point to the right if positive
and to the left if negative.
As the exponent is = 3 then the mantissa becomes = 1010.0100 1100 1100 1100 1 101,
therefore:-
1010 = (1x23) + (0x22) + (1x21 ) + (0x20) = 10 and
0100 1100 1100 1100 1101 = (0x2
Therefore the word value
Consequently, for sensor 1 register 0001 = 4124 and register 0002 = CCCD
2) - 0.0000045
sign bit = l
Exponent = -18, therefore exponent field = 127 + (-18) = 109, and bits 30 to 23 = 01101101
Mantissa = 1.179648 which in binary representation = 1 .00101101111111010110101
i.e. (1x2 ) + (1x2
-18
Therefore the word value
Consequently, for sensor 1 register 0001 = B696 and register 0002 = FEB5
Register Configuration M
15 14 13
r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w
Unsigned integer / 10
Range = 0 to 6553.5
66
) + (1x2
-1
= 0100 0001 0010 0100 1100 1100 1100 1101
= 4124CCCD
) + (1x2 ) etc = 0.0000045
-21 -23
= 1011 0110 1001 0110 1111 1110 1011 0101
= B696FEB5
12 11 10 9
Promet EExd User's Manual
) + -- + (1x2
-2 -20
8 7 6 5 4
97090 Issue 16, April 2019
) = 0.3
3 2 1 0