NAME

       modbus_write_and_read_registers - write and read many registers in a single transaction

SYNOPSIS

       int modbus_write_and_read_registers(modbus_t *ctx, int write_addr, int write_nb, const
       uint16_t *src, int read_addr, int read_nb, const uint16_t *dest);

DESCRIPTION

       The modbus_write_and_read_registers() function shall write the content of the write_nb
       holding registers from the array src to the address write_addr of the remote device then
       shall read the content of the read_nb holding registers to the address read_addr of the
       remote device. The result of reading is stored in dest array as word values (16 bits).

       You must take care to allocate enough memory to store the results in dest (at least nb *
       sizeof(uint16_t)).

       The function uses the Modbus function code 0x17 (write/read registers).

RETURN VALUE

       The modbus_write_and_read_registers() function shall return the number of read registers
       if successful. Otherwise it shall return -1 and set errno.

ERRORS

       EMBMDATA
           Too many registers requested, Too many registers to write

SEE ALSO

       modbus_read_registers(3) modbus_write_register(3) modbus_write_registers(3)

AUTHORS

       The libmodbus documentation was written by Stéphane Raimbault
       <stephane.raimbault@gmail.com[1]>

NOTES

        1. stephane.raimbault@gmail.com
           mailto:stephane.raimbault@gmail.com