With the Sag Rod for Roof Purlins command, sag rods are defined between purlin groups coming from both directions on the roof.
Location of Sag Rod for Roof Purlins Command
You can access it under the Ribbon menu Steel tab, Steel heading.
Click the sag rod for roof purlins icon.
Select the purlin group in the first direction you want to create the sag rod.
Select the other group of purlins in the second direction.
Your tension rods will form.
You can use sag rod for roof purlins command as well as for different purlin groups in the same direction.
Purlins in different directions before sag rods are created
Selecting the purlin group in the first direction to which the sag rod is intended to be created.
Selection of the second direction purlin group
Formation of sag rods