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modbus_read_input_registers() modbus_read_input_registers() Name modbus_read_input_registers - read many input registers Synopsis int modbus_read_input_registers(modbus_t *ctx, int addr, int nb, uint16_t *dest); Description The modbus_read_input_registers() function shall read the content of the nb input registers to address addr of the remote device. The result of the reading is stored in dest array as word values (16 bits). The dest array must be allocated with at least nb * sizeof(uint16_t) bytes. It is the caller's responsibility to ensure the buffer is large enough to hold all the registers to be read. The function uses the Modbus function code 0x04 (read input registers). The holding registers and input registers have different historical meaning, but nowadays it's more common to use holding registers only. Return value The function shall return the number of read input registers if successful. Otherwise it shall return -1 and set errno. Errors * EINVAL, the ctx or dest argument is NULL, or nb is less than 1. * EMBMDATA, too many input registers requested (nb > MODBUS_MAX_READ_REGIS- TERS). See also * modbus_read_input_bits <modbus_read_input_bits.md> * modbus_write_register <modbus_write_register.md> * modbus_write_registers <modbus_write_registers.md> modbus_read_input_registers()
Name | Synopsis | Description | Return value | Errors | See also
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