Xbee S2C PRO is not receiving periodically at every 200ms,when serial data sent at 200ms

i am working with 2 Xbee s2c pro modules.One Xbee is sending Serial data packet at every 200ms,but receiving xbee is receiving all the data at a time approximately at 1 sec intervals instead of being synchronous to Transmitting xbee,i.e.receiving xbee should receive one packet each 200ms