icm/ccms_refresh_rate is a SAP Parameter attribute which is used to control Time interval (sec.) for CCMS alerting information of ICM information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Interval for updating the status information of the ICM and SAP Web
Dispatcher to CCMS monitoring (see also
See SAP Parameter Documentation for full SAP documentation for this profile parameter.