VFM-60
Vortex Flowmeter
Rev1.3
Date:24/04/2020 User’s Manual
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00 : Register address higher
N3 CRC move 1 bit right , if move out is 1 bit
01 : Register address lower
N4 CRC=CRC XOR A001H
00 : Register quantity higher
N5 if move out is 0 , CRC=CRC
04 : Register quantity lower
N6 Move right for 8 times to finish the N1 calculation
04 : Date quantity
N7 …
80 : Date 1
N8 XOR operation the CRCL and N11
04 : Date 2
N9 CRC move 1 bit right , if move out is 1 bit
80 : Date 3
N10 CRC=CRC XOR A001H
80 : Date 4
N11 if move out is 0 , CRC=CRC
CRCL : CRC Parity code lower
Move right for 8 times to finish the N11 calculation
CRCH
：
CRC Parity code higher
Get the CRC calibration value
6.4 The float date format of the instrument
The storage sequence of 4 bits float formate is as below:
Address: 0 1 2 3
Content:
MMMMMMMM MMMMMMMM EMMMMMMM SEEEEEEEE
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
