modbus_read_bits - read many bits
The modbus_read_bits() function shall read the status of the
nb bits (coils)
to the address
addr of the remote device. The result of reading is stored in
dest array as unsigned bytes (8 bits) set to
You must take care to allocate enough memory to store the results in
nb * sizeof(uint8_t)).
The function uses the Modbus function code 0x01 (read coil status).
The function shall return the number of read bits if successful. Otherwise it shall return -1 and set errno.
- EMBMDATA, too many bits requested