There are several ways to reset and reboot RCEs.
Reboot remotely using SDK
dsl_reboot <RCE_ID> --ifname <host_network_interface_name>
This will command the RCE to execute "sync" then "reboot".
For example:
dsl_reboot shasta/2/0/0 --ifname eth1.204
Reboot while logged in (Linux)
reboot_rce
This will make the RCE execute "sync" then "reboot"
Reset via COB using SDK
cob_rce_reset <shelf_manager_ip>/slot/bay/rce
This will command a COB to reset power to the RCE.