ReadHregs – 3, SlaveAddr, RegAddr16, ItemCount, SPAddr16, NumFormat
A ModBus Master script command
When processed this command will result in the SPLat master sending out a ModBus function 3 query (Read holding registers), then wait for and process the response.
Parameters are:
| Item | Bit Length | Description |
|---|---|---|
| SlaveAddr | 8 | An 8-bit slave address |
| RegAddr16 | 16 | The 16-bit, 0-based address of a holding register (4xxxx reference) in the slave. This will be the starting point for the read. |
| ItemCount | 8 | An 8-bit count of how many registers are to be read. The minimum is 1. The maximum is determined by available communications buffer size (documented elsewhere). ItemCount contiguous items will be read. |
| SPAddr16 | 16 | A 16-bit RAM address within the SPLat master’s RAM. The ItemCount 16-bit registers read from the slave will be stored, starting from this address, according to the SPMode parameter. |
| NumberFormat | 8 | Specifies the number format sent from the slave, either byte (8 bits), word (16 bits, standard) or float together with the endianness of the value. |