modbus_read_bits(3) debian man page | unix.com

MODBUS_READ_BITS(3)						 Libmodbus Manual					       MODBUS_READ_BITS(3)

NAME
       modbus_read_bits - read many bits

SYNOPSIS
       int modbus_read_bits(modbus_t *ctx, int addr, int nb, uint8_t *dest);

DESCRIPTION
       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 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 0x01 (read coil status).

RETURN VALUE
       The modbus_read_bits() function shall return the number of read bits if successful. Otherwise it shall return -1 and set errno.

ERRORS
       EMBMDATA
	   Too many bits requested

SEE ALSO
       modbus_write_bit(3) modbus_write_bits(3)

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

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

libmodbus 3.0.3 						    05/26/2012						       MODBUS_READ_BITS(3)