Setting up guest WiFi on Cambium E400 and preventing access to LAN

Hi,

I recently purchased a cambium E400 WAP which I am using in combination with a DrayTek 2760Vn modem/router.

I am trying to set up a guest network that allows access to the internet only and am looking for some help.

I can create a guest network on the E400 which has the appropriate splash page etc but I can still access the local network on 192.168.1.X

To prevent this I'm assuming I need to set some rules in the access tab under ACL but am not sure how to go about this.

Can anyone please point me in the right direction?

Thanks in advance.

Simon.