Prodys PortaNet User Manual page 21

When one input leaves the TalkBack line (line 2), this
input is disabled for security reasons. This way, this
input cannot enter the program line unintentionally.
However, it is possible to change this operation mode
from the web page. When the Recover Last Mode is
selected, the input will recover its previous status when
it leaves the TalkBack line.
PortaNet User Manual 21 of 156