how can I get all state vectors of state space block during simulation in Xcos?
You can get all output states of state space block by using a vector multiplication. For example, if the states are [x1 x2], you can extract the x1 state by multiplying the output by the vector [1 0]. Similarly, you can extract the x2 state by multiplying the output by the vector [0 1]. This vector can be defined using the "GAINBLK_f". This block can be found inside the "Mathematical Operations" category on the "Palette Browser".
Yes and the states (the x vector) are available on the output "y" because we define "y=C*X". So if you define C as an identity matrix of proper dimension, all your states are available on output "y".
You are welcome. I think you can safely consider C to be identity with its "number of rows" matching the "number of rows" of B. I dont see any reason how C affects your system's model.