It does not appear in the field, and can only be brought into play by the PSICOM Tracker who tries to place it near party members. The accompanying Uhlan will then focus its Guided Missiles attack at the Targeting Beacon, dealing heavy damage to anyone nearby. The Beacon itself is quite weak.
Targeting Beacon should be eliminated as soon as possible to prevent Uhlan's Guided Missiles attack. Alternatively, if characters are naturally attacking and moving away from the Beacon, it can be left alone until the Guided Missiles attack has ended.