The Memory Module is used for storage of process variables and
set-point variables. The Modbus registers 40002 - 40075 are RAM
memory and is used for process variables which change frequently
and do not need to be maintained when the power fails. The
registers 40076 - 40099 are EEPROM memory and can be used for
variables which are not written to often and need to be maintained
when the power fails such as set-points.