Microsensor MFE600E Operation Manual page 22

message. The message body consists of hexadecimal numbers.
Data definition: The cumulative amount is a 16-byte hexadecimal fixed point number, and the
instantaneous amount (including flow, velocity, etc.) is a 4-byte IEEE 754 single-precision floating point
number.
Communication command: Function code 03（or 04）- reading display data
01
03
00
00 Register address low (display address)
00
02
CRCH
CRCL
For a multi-byte number transmission, use the BIG-ENDIAN format, that is, use the format with
high-weight bytes first and low-weight bytes after transmission. For example, a four-byte number
ABCDEF12H, the transfer order is: D0= ABH, D1=CDH, D2=EFH, D3=12H。
For a two-byte number such as 12ABH, then D0=12H, D1=ABH。
For floating-point numbers, the format is IEEE 754 single-precision, and the transmission order is the
high byte first and then the low byte. The high byte is the byte where the sign bit and exponent bit in the
floating-point number are located, and the low byte is the byte where the mantissa is located.
Above D0, D1, D2, and D3 respectively correspond to D0, D1, D2, and D3 in the transmission data
sequence described later.
According to the MODBUS RTU protocol specification, the maximum number of data bytes allowed to be
transmitted in one communication is 250 (125 × 2).
Parameter storage
TPTR
00
02
03
05
07
08
0A
0C
0D
0E
Table 12
Send
Address
Function code
Register address high
Register numbers high
Register numbers low
CRC Check code is high
CRC Check code is low
Table 13
Explanation
Instantaneous flow information
Instantaneous flow unit information
Positive total integer low
Positive total decimal place
Positive total unit
Reverse total integer low
Reverse total decimal places
Reverse total unit
Excitation alarm
Electrode alarm
01
03
04
80
04
80
80
CRCH
CRCL
Data type
FLOAT
SHORT
LONG
FLOAT
SHORT
LONG
SHORT
LONG
FLOAT
SHORT
20
Receive
Address
Function code
Byte numbers
Data 1
Data 2
Data 3
Data 4
CRC Check code is high
CRC Check code is low
Data length
4
2
4
4
2
4
4
2
2
2