Changing levels of support
RNR support can be turned on or off between sessions or between IMS restarts, and it can be changed at any level: in the IMS PROCLIB member, in the ETO logon descriptors, and in the Logon exit.
After RNR has been set on or off, it is not applied until the next session cold start. For IMS terminals (non-ISC, Finance and SLUP), the result is that the last RNR option selected becomes active at each logon. For ISC, Finance, and SLUP terminals, the result is that the last RNR option selected spans multiple logons and IMS restarts and becomes active only at the next session cold start.