Instruction Of Rs485 Modbus Communication; Interface Regulation - Bell VFM60 Series User Introduction Manual

To set a new password, users have to input the correct password twice, the password will become
effective only if the both inputs are the same; or users have to input again. If the power is off during a
password setting process, the password will be 2000 as default. When a password becomes effective,
users have to input the correct password before he can set the flowmeter, please reference to picture 5.6.
If users input incorrect password 3 times consistently, the display will come back to normal display
If a password has been set to a VFM60 vortex flowmeter, users can enter code setting C48=01 to set a
new password.

6 Instruction of RS485 Modbus Communication

6.1 Interface regulation

The communication interface should be RS485, the range of Baud rate should be 1200~115200.
The wiring terminal is "A" and
The communication should comply with MODBUS-RTU statute.
The combination of a communication signal: Address code - function code – date segment –
CRC calibration code. The distance between two characters should not be longer than one
character, or it will be considered as the beginning of a new message or the end of a old
message. The message is combined with hexadecimal arrays.
Defination of the dates: Please reference to the chart 6.1 below.
Register
address
0~1
2~3
4~5
6~7
8~9
10~11
12~13
14~15
16~17
18~19
20~21
22~23
Date:24/04/2020
SPI
0000
Picture 5.6 Password input
"B".
Chart 6.1 Address of the displayed date
Usage Nature
Flow rate Read only
Frequency Read only
Reserved Read only
Pressure Read only
Temperature Read only
Density Read only
Reserved Read only
Reserved Read only
Reserved Read only
Reserved Read only
Reserved Read only
Reserved Read only
27 / 59
VFM-60
Vortex Flowmeter
Date type
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Rev1.3
User's Manual