what is the difference between XBEE PRO S2 and S2B


   I want to know the difference between XBEE-PRO S2 and S2B.

It is simply a different revision to the XBee PRO ZB modules. The S2B is designed so that it can have a 2nd processor populated or not on the same PCB where as the S2 didn’t. The S2B also adds some additional components external to the Ember processor that allows for additional channels that were not possible before.