Modbus TCP

Data Source Endpoint

plcIP:plcPort (plcPort defaults to 502)

e.g. 192.168.2.2:502

Data Tag Address

register

• register- The location of the tag in the holding register.

e.g. "452" or "12"

Modbus Also accepts the following fields as options

• scale - multiply the read value to scale the intial read value

• functionCode - Modbus hold registers in different areas as described by a function code

  • 3 - Input Registers

  • 4 - Holding Registers

• bytesToRead - the number of bytes to read

• dataType - the data type we should convert the read data to (defaults to UInt16)

  • can be any of the following

    ['int8', 'uint8', 'int16', 'uint16', 'int32', 'uint32', 'int64', 'uint64', 'float', 'double', 'utf8', 'ascii']

• endianness - Use either big (BE) or little (LE) endianness on the value. (default to BE)

• deciamls - if using a float data type, then due to precision errors you may numbers with lots of decimal places. This helps round the number.

e.g. {"scale":0.0001,"functionCode":3,"bytesToRead":2,"dataType": "int32","endianness":"BE"}