Please note that modscan32 does not support embedded modbus messages in a TCP/IP packet. Modscan32 uses MBAP messaging, which is what the ProLinx driver uses on port 502. In order to use port 2001, and have that data pass-thru to port 0 modbus master port, you'll need a software package that creates a virtual comport on your pc. Modscan32 will then connect to ie: com8 which is the virtual comport. If you don't have a Modbus slave connected to port 0, it will timeout regardless of your Modbus TCP status.
ProLinx Modbus TCP/IP EtherNet