The TXF-125E and TXF-125DM (Double Modulation) are battery operated quad photoelectric beam sensors designed for compatibility with leading wireless systems; reducing the time and cost of permanent installations and allowing the use of Active Infrared Beams on rapid deployment or temporary installations. With 4 selectable frequencies, multiple beam sets can be used in both linear and stacked configurations without risk of crosstalk, further assisted by a transmitter power function that allows the user to set 83’/165’/248’/330’zones.