problem: loading firmware to ic697cmm742

I could not change firmware of IC697CMM742 from 2.84 to 2.2.0 . I performed all steps that is described to upgrade cmm742 firmwares with no luck . due to my HMI and its software network(s8000_e) I think I have to load 2.2.0 firmware version on cmm742.Am I right?.Is it possible to downgrade CMM742(LL OR KL OR...) from 2.84 to 2.2.0 principally? how can I perform that? I mean if I must do any special things else?
PLC: GE 90-70(ALSTOM C80-75)
HMI:P1200
NETWORK: S8000_E
thanks in advance