Your question is a touch vague, lots of possible answers, but, I'll give it a try.
A guide
line cable would refer to a gable used to guide/control/contain the movement of a
wire guide
counterweight arbor or the
edge of a
wire guide
fire curtain. The
counterweight arbor guide(s) there are two per
arbor, are located at the front and rear of the
arbor and run from tie off points at the floor/
rail to the headblock/
grid.
Fire Curtain guides are located at the back, inside of the
smoke pocket. Usually anchored to the floor with an eye plate and run to the
grid where they are anchored to the building steel with chains or brackets or eye bolts.
However, did you mean "GUY"
line cable??? If so, guy
line is a tension bracing method for
ground supported
truss structures. It can be used around the perimeter or across areas needing bracing. For the perimeter, the guys are attached at or near the top
edge of the structure and run down and out at an angle usually between 45 and 60 degrees. The lower end is attached to earth anchors, concrete Jersey barriers, water tank ballasts or similar multi-ton tie-off points. Guys are also used in pairs as tension member X bracing across the sides or back of structures. They are also used as horizontal X bracing at the roof
level to resist torsion or twisting of the structure under various wind loading conditions. Tension on X braces, size of cable and load ratings of components, the amount of
ballast weight or earth anchor
rating and placement are different for each setup and must be determined by an engineer qualified to calculate the various loadings for the type and size of
truss in question, for the particular setup in question. Additional wind load calculations are made for the elements that will be supported by the
truss such as Show poster front scrims, side wind walls, the 15' x 20'
LED video wall. For example, one of our roof structures that goes on a semi tomorrow for a week in Missouri has an 8
page engineering report from the manufacturer with pages of various wind speed and uplift conditions with wind from 8 quadrants, with the roof at various heights.
Anyway, that's it in brief. Hope I answered the question you were asking.