If you are looking to log data from a PLC or a Modbus device, you can use AdvancedHMI. It has a BasicDataLogger. If that doesn't do exactly what you want, you can use a DataSubscriber and write some VB code to log exactly as you want.
These connect to your PC directly or can be added to your Ethernet router. Then, you can connect using EZ Datalogger via Modbus TCP protocol and log data to your PC.
If you already have other software(Labview, Wonderware, Indusoft, etc.), it very likely has the ability to communicate to our modules using Modbus TCP.