Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
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 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 StA(C)phane Raimbault
       <stephane.raimbault@gmail.com>

libmodbus v3.1.6		  08/10/2020		   MODBUS_READ_BITS(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | SEE ALSO | AUTHORS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=modbus_read_bits&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help