You need to use following command to poweroff the IDSM-2 module from the module-
reset [powerdown]
The reset command without any options will cause the IDSM-2 to perform an orderly reboot. If you add the powerdown option, the IDSM-2 will perform an orderly shutdown and will either power off the device or place it in a state where it can be powered off.
Regards,
Vibhor.