Function Keys in console

I’ve set up ttylinux on an old computer to use as a terminal to connect using ssh to a UNIX server to run an application that relies on the function keys. The problem is that when logged into the console, the function keys return A, B, C and D. When I connect to the ttylinux workstation using putty, the function keys work as expected.

Does anyone have any suggestions on how to get them to work on the console?