Control/Dependant Releases for Beam on Top of Beam

Hi, 

I have a beam on top of a beam, see highlighted beams in the image below:

I am using a Control/Dependant relationship to connect them as they are at different levels:

I currently have Node 102 (the top beam) as the control.

This is an existing structure. Both beams are channel sections that are bolted together. It is a pin connection.

To model this correctly and avoid errors, which degrees of freedom should I fix? 

I have Hinged both ends of the top beam, so should I just fix all 6 DOF. Will STAAD recognise that the beam is hinged and then only transfer the relevant forces if I fix all 6 DOF?

Or should I fix Fy, Fx, Fz & Mx and release My & Mz - just like a hinged end of a beam?

Thank-You for your help,

Ryan