If you just want to communicate with the radios, the easiest way would be to add another ip address to the network adapter that is going to your AP.
You can put any number of addresses on one adapter, simulating multiple network cards sharing the same wire.
To do this, you’ll have to ensure the LAN side adapter’s ip address is set statically, not with DHCP. Though, as you’re serving DHCP off of this card, you probably have this set statically already. If I understand your setup, this will be the gateway address of your LAN.
To add another ip to the LAN facing card…
1. Go to the network properties of your adapter
2. Internet Protocol (TCP/IP) -> Properties
3. Click on ‘Advanced’
4. Click on ‘Add’
5. Enter an IP address and subnet mask on the radios network.
Now you can connect to the radios from the router machine.
Depending on how you have routing set up, (I’m a little fuzzy on windows routing services), you may or may not need to configure something to allow other clients on the wireless to access the radios.
If the radios can be accessed through the wireless, you could also just set your wireless computer with 2 static addresses, one on both networks, as well.
Hope this helps!