NAME

       hal_signal_new, hal_signal_delete, hal_link, hal_unlink - Manipulate HAL signals

SYNTAX

       int hal_signal_new(const char *signal_name, hal_type_t type)

       int hal_signal_delete(const char *signal_name)

       int hal_link(const char *pin_name, const char *signal_name)

       int hal_unlink(const char *pin_name)

ARGUMENTS

       signal_name
              The name of the signal

       pin_name
              The name of the pin

       type   The type of the signal, as specified in hal_type_t(3hal).

DESCRIPTION

       hal_signal_new  creates  a new signal object.  Once a signal has been created, pins can be
       linked to it with hal_link.  The signal object contains the actual storage for the  signal
       data.   Pin  objects linked to the signal have pointers that point to the data.  'name' is
       the name of the new signal.  It may be no longer than HAL_NAME_LEN characters.   If  there
       is already a signal with the same name the call will fail.

       hal_link links a pin to a signal.  If the pin is already linked to the desired signal, the
       command succeeds.  If the pin is already linked to some other signal, it is an error.   In
       either  case,  the  existing  connection  is  not modified.  (Use 'hal_unlink' to break an
       existing connection.)  If the signal already  has  other  pins  linked  to  it,  they  are
       unaffected  -  one  signal can be linked to many pins, but a pin can be linked to only one
       signal.

       hal_unlink unlinks any signal from the specified pin.

       hal_signal_delete deletes a signal object.  Any pins linked to the object are unlinked.

RETURN VALUE

       Returns a HAL status code.

SEE ALSO

       hal_type_t(3hal)