Inovonics EN1235DF Double-Button Fixed Position Hold Up Transmitter

The Inovonics EN1235DF is a fixed-position, double-button wireless hold-up transmitter designed for discreet emergency alarm activation in commercial intrusion and duress monitoring systems. Using EchoStream 902-928 MHz frequency-hopping wireless technology, it transmits an alarm when both buttons are pressed simultaneously, helping prevent accidental activation. The transmitter features back and housing tamper protection, an LED transmission indicator, and supervised communication with a three-minute check-in interval. Powered by a replaceable 3V CR2 lithium battery with a typical three-to-five-year service life, the compact, UL-listed device supports concealed indoor mounting with compatible Inovonics receivers.

Inovonics EN1235DF EchoStream Double-Button Fixed-Position Wireless Hold-Up Transmitter

The Inovonics EN1235DF Double-Button Fixed-Position Hold-Up Transmitter provides discreet manual emergency signaling for commercial security and duress alarm applications. Part of the Inovonics EchoStream wireless security platform, the transmitter features two activation buttons that must be pressed simultaneously to initiate an alarm, reducing accidental triggering from unintended contact. Its fixed-location design supports concealed installation beneath desks, transaction counters, reception workstations, and other accessible indoor locations where personnel may need to request emergency assistance. The device incorporates back and housing tamper protection to detect unauthorized removal or interference. Unlike portable belt-clip or necklace transmitters, the EN1235DF is designed for permanent mounting and supervised operation within a compatible wireless security system.

The EN1235DF communicates using EchoStream frequency-hopping spread-spectrum (FHSS) technology across the 902-928 MHz North American frequency band. Pressing both buttons simultaneously initiates multiple wireless alarm transmissions, with an integrated LED flashing during each transmission to confirm transmitter activity. Releasing the buttons sends an alarm restoration message to the receiving system. When properly enrolled and supervised, the transmitter sends an automatic check-in message every three minutes, allowing the connected receiver to monitor wireless communication and device availability. The unit features a factory-programmed identification number for individual enrollment and supports compatible Inovonics EN4000, EN4204R, EN4216MR, and EN4232MR receivers, along with other manufacturer-approved EchoStream equipment. Alarm processing, notification, and monitoring responses are determined by the connected security system.

The Inovonics EN1235DF operates from a replaceable 3V CR2 lithium battery, with a manufacturer-specified typical service life of three to five years, depending on operating conditions and transmission activity. Its compact black housing measures 3.0 inches long, 1.6 inches wide, and 0.72 inches deep (76 40 18 mm) and weighs approximately 1.6 ounces (45 g). The transmitter operates in temperatures from 32 F to 140 F (0 C to 60 C) and relative humidity up to 90% non-condensing. Its internal reset button initializes the device after battery installation and supports receiver enrollment, while the frequency-selection jumper accommodates approved regional operating bands. For North American installations, the transmitter uses the 902-928 MHz band. The battery-powered design eliminates the need for external power wiring at the protected location.

The EN1235DF includes a mounting backplate and two installation screws for secure attachment to a suitable indoor surface. The integrated back tamper switch must maintain contact with the mounting surface; otherwise, the device reports a tamper condition. For UL installations, Inovonics requires concealed placement where transmitter operation cannot be observed from a public area. The manufacturer recommends weekly functional testing to verify that the receiving system recognizes alarm activation, restoration, and tamper conditions. The EN1235DF is documented for UL 365, UL 636, UL 1076, and UL 1610 applications, with FCC and RoHS compliance, and carries a 24-month limited manufacturer warranty under the published installation instructions. Its double-button operation distinguishes it from the EN1235SF single-button fixed-position transmitter and the EN1235D portable belt-clip model. Installation requires a compatible EchoStream receiver and correctly configured alarm monitoring equipment, selected according to the applicable system listing and security requirements.