Dear Provas,
It will be more helpful if you explain in your post as for what purpose you wish to assign Master Slave Command. Master Node selection depends on kind of rigidity you want to create between the connecting nodes.
But if you want to create a rigid diaphragm using master slave I recommend to have master node at center of gravity of that particular slab.
Although we have rigid diaphragm option where STAAD will calculate the position of master node and assign a virtual node at that location which is not physically present in the model. I recommend this option if you have any rigid diaphragm in your model.
It will be more helpful if you explain in your post as for what purpose you wish to assign Master Slave Command. Master Node selection depends on kind of rigidity you want to create between the connecting nodes.
But if you want to create a rigid diaphragm using master slave I recommend to have master node at center of gravity of that particular slab.
Although we have rigid diaphragm option where STAAD will calculate the position of master node and assign a virtual node at that location which is not physically present in the model. I recommend this option if you have any rigid diaphragm in your model.