xbee 24-b to xbee 24-zb

i have old xbee module part number is xbee 24-bwit-004 module the actual firmware version is znet. i am able to upgrade the firmware to current firmware version (s2b firmware). but i am unable to communicate with new xbee pro s2b module or xbee - s2c

is it possible to communicate between this module?
if possible please give a suggestion.

Yes it is. Check your channel mask. You may need to adjust it on the S2B and S2C to accommodate the S2.