Hello There are couple of settings to be made. Simulate the hardware in CBM by right click on Properties of controller Enable HW simulation to true in Tools>> Setup>>Application Download. Change controller ip to default Softcontroller ip by browsing to log file of Softcontroller set up.
This will lead to simulate your program.
Even though if you face the problem increase the Heap memory in set up wizard for softcontroller to 500MB and check for download.