modbus tcp/ip

I am working on a project in which I have to use Modbus tcp/ip in s7 300.

my CP is CLIENT and SLAVE is my PC.

until now my parameterization is complete and I am able to write values on SLAVE, but my CP is not reading values from PC.

what must be the problem ... ?

need help ...

What type of application is your Modbus/TCP slave running on a PC?

Is it a generic Modbus program like Modscan32 or Modpoll's slave?

Or is it an application involving I/O cards?

Did you write the slave application or is it a commercial Modbus slave?