The 4-wire system was developed around the 1990s by a Swiss developer for the electronic safe locks from La Gard. The system is named after the 4-core cable that leads from the entry unit outside through a hole to the lock inside the safe. However, the entire structure of the (analog) electronics for transferring the input of a user from the keyboard to the lock is called “4-wire system”. Since every single contact of a connector is a potential problem with safes (due to vibration, corrosion, metal dust), this solution has obvious advantages. At the same time, of course, such a cable is also less expensive.
Keyboard connector La Gard / NL Lock in the 4-Wire System
Previously, La Gard had an 8-pin system with Western plugs that were much too big for the spindle/cable hole in the safe door. For this reason, the plug had to be cut from the cable during installation, and a new plug had to be crimped on after passing the cable through the hole. Today these connectors are still being used for instance on patch cables for network connections.
NL Lock and other lock manufacturers later took over the 4-wire system. This means, for example, that most La Gard locks can be operated with NL Lock keyboards and vice versa. However, neither manufacturer gives a guarantee in this case. To the contrary of La Gard, was NL Lock giving licenses to other manufacturers including Tecnosicurezza, Intergard, Wittkopp, and M-Locks. The keyboards of these manufacturers, together with NL lock locks, were often even VdS certified. In our webshop we have a large selection of 4-wire keyboards and locks from different manufacturers.
Plug socket on an NL lock lock