How can I setup a win 7 PC as a router?

Solution 1:

To forward packets (act as a router) between attached networks you can change/create a registry setting:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Value Name: IpEnableRouter
Value Type: REG_DWORD
Value Data: 1

To modify the static routing table use the route command.

To check it has been enabled use ipconfig /all and there should be a line:

   IP Routing Enabled. . . . . . . . : Yes

Ref: Microsoft Support article: Enabling IP Routing

Solution 2:

If all devices are connected to a NIC on the industrial PC, you would simply need to connect to the PC using Remote Desktop. You can then connect to the other devices.

We use Dameware or VNC to make the conenction to the Industrial PC and the open an RDP conenction to the other connected PCs. In some cases it is only needed to manage controls software on the Industrial PC for assoiated devices like cameras or PLCs.

You do not need to configure much, especially if you connect to the other subnets by IP.