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)

LinuxCNC Documentation                             2006-10-12                               hal_signal_new(3hal)