Alarm receiver
for receiving 2-way audio and listen-in and all other alarm codes

For Contact-ID and Pulse 4X2

Copyrights Micro Seven, Inc.®, 2009-2015

LS15F contains two simulated telephone lines, two FXS ports. LS15EA-LISTEN-IN contains one regular PBX port (FXO) and one simulated telephone line (FXS). One line is to receive alarm message, and the other line is to connect incoming telephone call to a telephone set for 2-way audio. An alarm panel is connected to Line 1 of LS15F with a piece of telephone cord with no PBX or PSTN line required. An alarm panel is connected at line 2 of LS15EA-LISTEN-IN via PBX or PSTN. Received alarm messages are transmitted in ASCII data to PC for displaying decoded alarm messages by using provided Windows compatible software. When non-listenin alarm messages are received by LS15F, LS15F or LS15EA-LISTEN-IN hangs up the received calls. When a listen-in alarm message is received by LS15F or LS15EA-LISTEN-IN, it will not hang up the received call. It generates high voltage signal at line 2 for LS15F or line1 of LS15EA-LISTEN-IN to ring a telephone set. When a receiver of the telephone set is lifted, a two-way audio path is established between the call from the alarm panel and telephone set.  LS15F may be configured as a general purpose telephone line simulator as model LS15-C1.



Features of Alarm-Receiver Simulator portion of LS15-F and LS15EA-LISTEN-IN

i Small, 4" x 1.75" x 7.5"
i AC/DC Operation
i Security Industry Association’s Ademco® Contact ID and Pulse 4X2 protocols-note: Pulse 4X2 is not available for LS15E.
i Generation of handshake and kiss-off tones
i No calibration required for frequency and amplitude adjustment of handshake, kiss-off, and call progress tones
i RS232C interface to transmit alarm messages to PC and the alarm receiver software provided
i Alarm-receiver simulator from line 1 and telephone output at line 2 for LS15F
i Battery-feed (loop current) for simulated telephone line port at line 1&2 of LS15F and line 1 of LS15EA-LISTEN-IN
i Internal audio monitor for LS15EA-LISTEN-IN
i Testing listen-in function between alarm panel and central station
i Ring signal generation

Application and benefit of alarm receiver

i Demonstration and testing alarm control panels at factories and fields
i Complete testing of alarm panels before the installation
i No alarm receivers required for testing alarm control panels
i Complete testing of alarm panels before the installation




Traditionally, when alarm panels are tested in the manufacturing or demonstrated in the sales offices, alarm receiver with two public telephone lines are required in addition to a computer. The Micro Seven model LS15F eliminates an alarm receiver and two telephone lines by combining both of telephone line simulator and alarm receiver functions for the application. Here, an alarm panel is connected to the line 1 of LS15F. The RS232C port of a PC is connected to the rear panel connector of LS15F with special cable and connector that are provided with LS15F. Micro Seven’s LS15F alarm receiver software decodes received alarm messages. First, the alarm panel goes off-hook at line 1. The loop current is flowing at the line 1.  Then, the alarm panel dials either primary telephone number (single digit) or secondary telephone-number that is assigned for line 2(programmable one) depending on which telephone number scheme is selected. When the dialed number is correct, the LS15F provides ring-back tone for two seconds. Then, there is no sound for four seconds. And ring-back tone is generated for two seconds. After 0.6 seconds, the LS15F transmits handshake tones of 1400 and 2300Hz for 100 ms each separated with 100 ms silence period. When the alarm panel receives the handshake tones, the alarm panel transmits a string of alarm message in DTMF tones with a check-sum at the end. When the alarm message with correct check-sum is received by LS15F, it transmits the kiss-off tone to the alarm panel. LS15F transmits the ASCII equivalent of the alarm message at the RS232C interface to the PC. Then, the alarm panel either transmits a new alarm message after a short delay or hangs up with the telephone line to terminate the call. If the alarm panel did not receive the kiss-off tone, the alarm panel may repeat transmitting the same alarm message four times. When LS15F sees the on-hook-state, it turns off the loop current for a few hundred milliseconds as a disconnect signal. Then, LS15F is now ready for a new call from the alarm panel. LS15F is compatible with the Ademco ® Contact ID Protocol for Alarm System Communications. Programmed parameters are restored upon powering off and on unless noted. It also transmits disconnect signal if LS15F does not receive any more alarm messages for few seconds unless the command was “Listen-inE command type.

If the received alarm message is “Listen-inEcommand, ring signal is produced at a telephone set at line 2 for two seconds on and four seconds off. When the ring signal is answered by lifting a receiver of telephone set, 2-way audio circuit is established between alarm panel’s speaker/mic and telephone set at line 2 of LS15F. When either telephone set or alarm panel’s speaker/mic circuit is hung up, audio circuit is disabled and both lines in on-hook.

Standard alarm receiver software, that is provided at no charge, “as is” with no support, no liability, and no support from Micro Seven. LS15EA-LISTEN-IN with FXO port receives alarm messages at FXO interface instead of FXS port in LS15F.




Note on special features about handling listen-in command:

Contact ID Listen-in command with 606 alarm code is received, ring signal is produced at the other line if the other line is on-hook condition. The hang-up timer is automatically disabled. Until ring signal is answered by off-hook condition at a telephone set of the other line, LS15F continues receiving alarm messages and transmitting ASCII equivalent of alarm messages via RS232 interface to PC. 2-way audio circuit is enabled between speaker/microphone at alarm panel and the telephone set. Hanging-up telephone line at either the telephone set at LS15F or alarm panel resets telephone line conditions at both lines at LS15F. Either line may receive listen-in command if both lines are enabled as alarm receivers/simulators using control software except LS15F may receive alarm signal at one line at a time.


Telephone number receiving for LS15F:

1.      Primary telephone number

2.      Secondary telephone number

DTMF dialing signal power: -13dBm to +5dBm per a frequency with maximum 4dB difference between frequencies.

Pulse dialing: Break period: 45 to 75 ms (60 ms nominal), make period: 30 to 60 ms (40 ms nominal)


DTMF detecting signal power for alarm messages: -23dBm to +5dBm per a frequency with maximum 4dB difference between frequencies

Alarm message DTMF signal on time (Burst ON time): 50 ms minimum

Alarm message DTMF signal off time (Burst OFF time): 50 ms minimum 400 ms maximum

Note: Contact ID protocol requires Burst ON and OFF times to be 50 ms minimum and 60 ms maximum.

Handshake tones:

1400: 1400+/- 1Hz, duration of 100 ms +/- 1.5 ms, silence period of 100 ms +/- 1.5 ms, and

2300Hz: 2300+/-2 Hz duration of 100 ms +/- 1.5 ms


Kiss-off tones: 1400 +/- 1 Hz with duration of 750 ms


Kiss-off and handshake tones amplitude: selectable among -14 dBm, -20 dBm, and -30 dBm by control software


Battery-feed voltage at line 1 and 2: (loop voltage): -20 volts


Off-hook impedance requirement at line 1: 400 ohms maximum DC, 600 ohms nominal AC


Call Progress Tones at line 1: single frequency or dual frequency type selected by control software


Programmable hang-up timer between alarm messages


Stutter dial tone at line 1: selected by control software


Line Input Jacks at line 1 and line 2: USOC-RJ11-C, standard modular phone jack


Front panel control:

Power switch

Power indicator

Line 1: RJ11 connector for alarm panel input (FXS)

Line 2: RJ11 connector for telephone set output (FXS for LS15F) or (FXO for LS15EA-LISTENIN)

Line Status Display: red LED for each line to indicate off-hook status, flashing for ring signal generation at line 2


Ring signal produced at line 2: 75volt RMS 20Hz sine wave, 2 sec on / 4 sec off timing


Rear panel control: RS232 connector, power connector, and 3.5 mm audio connector (for LS15EA-LISTEN-IN) for hearing dialing, handshake tone, kiss-off tone, and alarm messages using external audio power amplifier and speaker. LS15F does not contain an internal speaker.


RS232C Interface:

Speed: 1200 baud, with one stop bit, no parity bit

The interface signals: Receive Data, Transmit Data, Data Set Ready, Clear-to-send, and ground. The Data Terminal Ready signal is forced high at LS15F meaning that a PC is always ready to receive data from LS15F.

Connector: 9-pin D-sub on LS15F the rear panel

Cable(9-pin M/9-pin F) is provided.

Received alarm messages are computed for the checksum.


AC/DC Adapter: 117VAC +/- 5%, or 230VAC +/- 5%(for optional international AC/DC power adapter)

AC/DC Adapter or Car Battery Adapter input: 12VDC unregulated, 800mA maximum 

Line Status Display: red LED for each line to indicate off-hook status (continuous on) 

Calibration: not required because digitally synthesized tones

Power-On Indicator: green LED display

Dimensions: 19 cm (4") W x 4.5 cm (1.75") H x 10 cm (7.5") L

Weight: 400g (0.8 LBS.)

Environmental: Operating temperature: 0 to 35 degree C, Humidity: 85% RH at 35 degree C

Warranty/Service: 6 months limited warranty. No warranty if any factory seal is broken. Service is performed at the factory, usually within 5 working days.



International AC/DC Adapter (117V input unit is a standard.)

LS15F for FXS interface for alarm panel or LS15EA-LISTEN-IN  for FXO interface


Reference: Digital Communication Standard-SIA DC-05-1999.09, Ademco Contact ID Protocol for Alarm System Communications


Warning: Alarm receiving software is provided at no charge, “as isEwith no support, no liability, and no support from Micro Seven. Any additional software requirement is custom. We provide no liability using LS15F and alarm receiving software to all people and companies including alarm panel users, alarm central station, telephone companies, and all distributors.


Made in United States of America

Micro Seven, Inc. ®
1095-K N.E. 25th Hillsboro, OR 97124 U.S.A.
phone: 503-693-6982, fax: 503-693-9742
Home Page: www.microseveninc.com
Email: sales@microseveninc.com