modbus_read_input_bits - read many input bits
int modbus_read_input_bits(modbus_t *ctx, int addr, int nb, uint8_t *dest);
The modbus_read_input_bits() function shall read the content of the nb
input
bits to the address addr
of the remote device. The result of reading is stored
in dest
array as unsigned bytes (8 bits) set to TRUE
or FALSE
.
You must take care to allocate enough memory to store the results in dest
(at least nb * sizeof(uint8_t)
).
The function uses the Modbus function code 0x02 (read input status).
The function shall return the number of read input status if successful. Otherwise it shall return -1 and set errno.
- EMBMDATA, too many discrete inputs requested