In legacy SCADAPacks (SP32/SP3xx). the maximum number of DNP3 events was ~20,000. This was a SCADAPack programmed with TelePACE or SCADAPack Workbench CAM3 firmware. The legacy SCADAPack E (3xxE, 53xE) could retain ~40,000.
If an end user is using a SCADAPack x70 RTU AND firmware 9.8.6 or greater, the maximum buffered events that can be configured for DNP3 and IEC-60870-5-104 is 100,000 events. The default is set to 5000 events. This is configured on the events tab in RemoteConnect.