The proximity detector is a block capable of detecting nearby living things. It has an extremly precise and accurate detecting range that can range up to 9 blocks in all directions. Once it detects a living thing, it will emit a redstone pulse to its surrounding alerting any trap or alarm system. The proximity detector can also selectively detect things. It can choose to detect players only, mobs only or both. However, the proximity detector will not be able to detect players holding a signal disruptor of the same frequency and this jams up the signal of things. The proximity detector also needs to be constantly powered by electricity thus making this machine slightly expensive.
By right clicking the proximity detector with a wrench, the proximity detector will be set into inverse mode. In inverse mode, the proximity detector will output redstone when players with a matching frequency is present. Otherwise, the output will be off.