➢ Communication port: it is the serial port used for connection to one or more slave sensors.
➢ Speed: it is the serial port communication speed (must be same speed set on the slave sensor).
Default= 9600 bps.
➢ Parity: it is the parity used in communication. Default= None.
➢ Stop bits: it is a communication parameter. Default= 1.
➢ Timeout: it is the protocol waiting time after sending a request. Default= 1000 ms.
➢ Retries: it is the number of attempts to send the request after a timeout without reply. Default= 2.
During the configuration, the Modbus RTU parameters for reading the data must also be specified. Refer to
the sensor documentation for this.
The Modbus RTU parameters are as follows:
➢ Network address: it is the sensor address.
➢ Command: it is the data request command to the sensor. It can be Read Holding Register or Read
Input Register according to the sensor specifications.
➢ Register: it is the register containing the data to be read. The first register starts from the address
0x0000.
➢ Data format: it is the format of the data produced by the sensor. Alpha-Log supports the following
formats:
o Floating: two 16-bit floating point registers. The byte ordering is defined by the Order of
bytes parameter.
o Integer16: 16-bit unsigned register.
o Integer 16s: 16-bit signed register.
o Integer32: two consecutive unsigned 16-bit registers.
o Integer32s: two consecutive 16-bit signed registers.
➢ Scale factor: for the integer data format, 16 or 32 bits, with or without sign, it is possible to specify
the division factor of the data to obtain a floating value.
➢ Order of bytes: in case the sensor has floating type data format, it is possible to define the ordering
of the 4 bytes ABCD that make up the data:
o ABCD: default endian.
o DCBA: little endian.
o BADC: big endian.
o CDAB: reverse endian.
➢ Define error value: if set to Yes, it enables the parameter Error value.
➢ Error value: is the value that the measure assumes in the event of an error. The default value
is -99999.
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