7.66 steering_element
- type: setup command.
- function: setup for use of a given parameter of a given element as a steering corrector.
- sequence: must precede correct.
- N.B.: any use of this command disables the built-in definition of HKICK, VKICK, and
HVKICK elements as steering elements.
- Command syntax, including use of equations and subcommands, is discussed in 7.2.
&steering_element
STRING name = NULL;
STRING element_type = NULL;
STRING item = NULL;
STRING plane = "h";
double tweek = 1e-3;
double limit = 0;
long start_occurence = 0;
long end_occurence = 0;
long occurence_step = 1;
double s_start = -1;
double s_end = -1;
STRING after = NULL;
STRING before = NULL;
&end
- name — Optional: the (possibly wild-carded) name of the element to add to the steering list.
If not given, then element_type must be given.
- element_type — Optional: the (possibly wild-carded) name of the element type to add to
the steering list. If not given, then name must be given.
- item — The parameter of the element to be varied.
- plane — May be either “h” or “v”, for horizontal or vertical correction.
- tweek — The amount by which to change the item to compute the steering strength.
- limit — The maximum allowed absolute value of the item.
- start_occurence, end_occurence — If nonzero, these give the starting and ending occurence
numbers of elements that will be included. N.B.: if wildcards are used, occurence number
counting is for each set of identically-named elements separately, rather than for the sequence
of matched elements.
- s_start, s_end — If non-negative, these give the gaving and ending position limits for the
end-of-element locations of elements to be included.
- after — The name of an element. If given, only elements that follow the named element in
the beamline are included.
- before — The name of an element. If given, only elements that precede the named element
in the beamline are included.