Modbus RTU configuration
View the RS485 port arrangement
Quantities (Number of measured quantities)
Select the number of physical quantities that you wish to capture from the sensor.
The value can be set from 1 to 10, the default value is 5.
Name
Enter an identifying name for each of the quantities to be acquired. You can
assign as the name, for example, the type of measured quantity. The name should
begin with a letter and can be maximum 12 characters long. The name unequivocally
identifies the measurement being input; you cannot assign the same name to multiple
measurements.
Unit (Unit of measurement)
Unit of measurement of the quantity detected by the sensor. It should begin
with a letter and can be maximum 12 characters long. The unit of measurement
should be in agreement with the value of the Gain parameter. if you do not want
to display and store the quantity, enter ---- (dashes) in the Unit
field.
Baud rate
Select the communication speed of the sensor.
Mode (Communication parameters)
Select the communication parameters. The following options can be selected:
• UART_8N1: no parity, 1 stop bit
• UART_8N2: no parity, 2 stop bits
• UART_8E1: even parity, 1 stop bit
• UART_8E2: even parity, 2 stop bits
• UART_8O1: odd parity, 1 stop bit
• UART_8O2: odd parity, 2 stop bits
Format (Format of data)
Select the format of the data transmitted by the sensor. The following options
can be selected:
• Integer 2B: 2 Bytes
• Long 4B: 4 Bytes
• Floating Point 4B: 4 Bytes
Address
RS485 address of the sensor.
Function Code
Select the function code of the Modbus command. The following options can be
selected:
• 03 Read Holding Registers
• 04 Read Input Registers
Start Register
Enter the address (not the number) of the register containing the first quantity
to be read.The number of consecutive registers to be read is determined by the
number of measured quantities.
Gain
The value recorded in the datalogger is the result of a linear formula applied
to the measured value:
Value recorded = Gain x Value measured
The Gain value is the same for all the quantities measured by the sensor. You should only enter the numeric value, without unit of measurement, in the Gain field. The unit of measurement should be entered in the Unit field. By setting Gain = 1, the recorded value is exactly the measured value.
Configuration of the sensor
For a correct functioning of the system, the sensor should be configured according
to the following settings:
1. The measured quantities transfer order should match the order programmed
in the datalogger.
2. The units of measurement set in the sensor should match the ones programmed
in the datalogger.
3. RS485 with Modbus-RTU protocol communication mode.
4. The RS485 Address must match the one programmed into the data logger.
5. The communication speed (Baud rate) must match the one programmed
into the data logger.
Error messages
If the configuration parameters are not correctly input, you can get the following error messages.
The name and Unit fields are required !
Cause: the identification name or the unit of measurement fields were not filled.
There is just an equivalent Name !
Cause: you previously entered a sensor with the same name. You should change
the identification name.
Gain must be not zero !
Cause: the Gain field has not been filled or zero has been entered.