Modbus communication between PLC and PIC32MX problem

Hello,

I am implementing modbus communication between PLC and PIC32MX. the PLC as a master is configured to use serial io scanner, modbus rtu . and excahnge and message blocks for the instruction commands to read register contents from slave which is the pic32mx. i am able to see the request command from plc at the slave side , and am able to send response from slave in which i test it in the transceiver's DI pin. but i dont see the the response getting in the input registers of the plc, am i trying to read in the wrong registers ? If i am not mistaken i should see the response in the exchange blocks or in the MW ( memory words ) corresponding to the reception table ? any help please