"To continue taking part in this (and in other major projects) we need all input/output modules to be adapted to work with Normally Closed (NC) contacts. Besides, it is necessary to have line control (or maybe it’s better to say control on the line) at the very input of the module in a way that an open-circuit fault signals that there is a malfunction, while unlocking in the device shows that there is a fire."
"Unlocking int the device" I'm not sure what you want to say, and there was no image attached.
Another is singular - other is for plural.
I hope this helps. Simon.