Modbus: Float Convert

The Modbus: Float Convert Node converts a number into an array of two 16-bit Modbus register values. This node supports multiple register and byte ordering formats so you can match the endianness required by Modbus-enabled device.

Node Properties

This node has three configuration fields.

Input Template

• Input Template: (Required) A string template that resolves to the numeric value to convert. The resolved value must be a valid number.

Examples:

• A template such as {{data.temperature}}

If the resolved value is not numeric, the node throws a validation error.

Endianness Configuration

The following endianness options are supported:

• big: Big-endian word and byte order (ABCD)
• little: Little-endian word and byte order (DCBA)
• bigByteSwap: Big-endian with bytes swapped in each word (BADC)
• littleByteSwap: Little-endian with words and bytes swapped (CDAB)

Destination Path

• Destination Path: (Required) A payload path where the resulting array of Modbus registers will be stored.

The value written to this path is always an array containing exactly two unsigned 16-bit integers.

Node Example

The following is an example of converting a value from the payload and storing the result for a later Modbus write:

{
  "data": {
    "temperature": 2.54
  }
}

With the following node configuration:

• Input Template: {{data.temperature}}
• Endianness Template: big
• Destination Path: modbus.output

The resulting payload will look similar to:

{
  "data": {
    "temperature": 2.54
  },
  "modbus": {
    "output": [16418, 47186]
  }
}

Node Errors

This node throws a validation error in the following situations:

• The Input Template does not resolve to a valid number.

An example invalid input error message is:

{
  "type": "Validation",
  "message": "inputTemplate value cannot be not-a-number, it must be a valid number"
}

Related Nodes

• Modbus: Write Node
• Modbus: Read Node