| To avoid errors in transmission, Vaisala recommends implementing the retry functionality for Modbus master software. If the sensor does not respond to the first Modbus query command, the same query is sent again. |
WXT530 has a non-isolated RS-485 serial line
as a Modbus interface. WXT530 uses 2 Modbus register ranges:
You can read the input registers and both read and write in the holding registers.
You can control device functionality and configuration in Modbus holding registers.
| Register range | Description | Register type |
|---|---|---|
| 1 - 11 | Device status | Holding |
| 1 - 31 | Commonly used unit system independent values | Input |
| 32 - 51 | Measurement values in metric units | Input |
| 52 - 71 | Measurement values in imperial units | Input |
| 72 - 112 | Other measurement values | Input |
The register values are expressed as 16-bit
integers with the use of suitable scaling factors (SF), if needed. The measurement values are
multiplied with a scaling factor and mapped to the 16-bit registers as an integer. The
register value ranges are:
- 0 … 65530 for unsigned (U) values. 65535 indicates an invalid or unavailable value.
- -32762 … 32762 for signed (S) values. 32767 indicates an invalid or unavailable value.