Gayatri,
For both SM Synchron and Free Run, the same DC settings apply for the ESC.
On TwinCAT, SM synchron RUN [Actions -> Activate Configuration] is launched differently from Free Run [Actions -> Set / Reset TwinCAT to Config mode, followed by Yes for free run].
To go to OP on SM Synchron, you need to have a task (a PLC program or even a dummy task) with process data.
Regards,
Srikant