The LPI is a current loop (4-20 and 10-50 mA) powered wireless (RF) transceiver designed primarily for hazardous (I.S.) short-range use (under 300 feet indoors). The transceiver draws its power from the current loop, and when not transmitting stores the energy in a super cap. The micro controller controls the frequency of transmission as well as LED indication of presence or absence of loop signal. A battery is used for emergency transmissions when the loop is not active to warn the operator of input problems.