The Float Date Format Of The Instrument; The Sequence Of The Float Date Bytes Of Instrument - Bell VFM60 Series User Introduction Manual

00 : Register address higher
01 : Register address lower
00 : Register quantity higher
04 : Register quantity lower
04 : Date quantity
80 : Date 1
04 : Date 2
80 : Date 3
80 : Date 4
CRCL : CRC Parity code lower
CRCH ：CRC Parity code higher

6.4 The float date format of the instrument

The storage sequence of 4 bits float formate is as below:
Address: 0
Content:
MMMMMMMM MMMMMMMM EMMMMMMM
Use IEEE standard method, do not store 1 on top digit, if top digit is 1, means negative; if top digit is 0,
means positive. So the 23 mantissas and a 1 on top digit, which is concealed, constitute a 24 bits fixed
point true form decimal, which is a decimal have mantissas less than 1 and more than or equal to 0.5.
The lowest 8 bits are exponent-marker using shift code method. The exponent marker equals to the
actual value minus 127. For example: 7=86H-7FH, -10=75H-7FH
e.g.: 100=0x00,0x00,0x42,0xc8
-100=0x00,0x00, 0xc2,0xc8
0=0x00.0x00.0x00.0x00 (exponent-marker is 0, the number is 0)

6.5 The sequence of the float date bytes of instrument

Code setting C38 is used for setting the sequence of the float date bytes of instrument.
Float date will occupy 4 bytes (2 registers). To set the bytes order of float date, please modify register:
1: LL_LH_HL_HH the lower 16 bytes registers come first, the lower 8 bytes within the 16 bytes
registers come first.
eg: 100=0x00,0x00, 0xc8, 0x42
-100=0x00,0x00,0xc8,0xc2
2: HH_HL_LH_LL the higher 16 bytes registers come first, the higher 8 bytes within the 16 bytes
registers come first.
eg: 100=0x42,0xc8,0x00,0x00
-100=0xc2,0xc8 ,0x00,0x00
3: LH_LL_HH_HL the lower 16 bytes registers come first, the higher 8 bytes within the 16 bytes
Date:24/04/2020
N3 CRC move 1 bit right , if move out is 1 bit
N4 CRC=CRC XOR A001H
N5 if move out is 0 , CRC=CRC
N6 Move right for 8 times to finish the N1 calculation
N7 ...
N8 XOR operation the CRCL and N11
N9 CRC move 1 bit right , if move out is 1 bit
N10 CRC=CRC XOR A001H
N11 if move out is 0 , CRC=CRC
Move right for 8 times to finish the N11 calculation
Get the CRC calibration value
1 2
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