System Enhancement Module (SEM) for VISTA w/ AT&T LTE and IP Communicator

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The ADC-SEM300-VT-AT is a system enhancement module that allows a VISTA P-Series Alarm Panel to connect with the servers. It connects across the AT&T LTE Network and an internet network using a wired ethernet connection. Buy the ADC-SEM300-VT-AT here.
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If you have a Honeywell VISTA P-Series Panel, then a communicator must added to get the system set up with alarm monitoring. The ADC-SEM300-VT-AT is unique in this aspect, as it allows a VISTA to work with, This dual-path SEM provides connectivity across both IP and cellular.

Normally, when you think of a Honeywell VISTA Panel, you think of it being used with the Total Connect 2.0 interactive platform, not However, has been releasing System Enhancement Modules (SEMs) that help the VISTA Systems connect with the platform instead. Really, there isn't much difference between and Total Connect 2.0 in most regards. One area where tends to thrive is in video surveillance, as their camera selection is deeper, and the Video Analytics features have a lot to offer. As a result, if you have a VISTA Panel, but you want to start building around the platform, then the ADC-SEM300-VT-AT might be perfect for you.

One of the best features about the ADC-SEM300-VT-AT is that it offers excellent reliability. The module communicates across both the AT&T LTE Cellular Network, and across the internet using a wired ethernet connection. If one pathway goes down or becomes unavailable, then it's no big deal, because the other communication path will ensure that the system stays monitored. It's also important to note that AT&T plans to support their LTE network well into the very distant future. Therefore, the ADC-SEM300-VT-AT should be able to provide a long-term monitoring solution for your system. Remember that you will need a monitoring plan with cellular connectivity in order to use this module. An example of such a monitoring plan is the Alarm Grid Gold Plan (Self or Full).

Another awesome function of the ADC-SEM300-VT-AT is that it doubles as a Z-Wave Plus Smart Home Controller. After it has been installed and activated, then a wide selection of Z-Wave home automation devices can be paired with the module, including lights, locks, programmable thermostats, and more. Although classic Z-Wave devices can be enrolled with the unit, you will get the maximum functionality out of the SEM by pairing Z-Wave Plus devices with it, as they offer a longer wireless range and battery life when used with a certified Z-Wave Plus controller like the ADC-SEM300-VT-AT. Remember, all Z-Wave operation and control will be limited to occurring through the platform, as there will be no way to perform Z-Wave operations locally at the panel when an SEM is used. This means that if there are any Tuxedo keypads being used on the panel, the user will have to choose between using those keypads to control Z-Wave devices, or using the SEM. The difference is that the Tuxedo Keypads will allow local-only touchscreen control, while the SEM and will allow the user to control their Z-Wave devices from any location.

This module is designed specifically for use with the VISTA P-Series Systems, including the VISTA 10P, 15P, 20P, and 21iP Systems. As a requirement, the VISTA Alarm Panel must have been manufactured in 2005 or later, and it must be running a certain minimum firmware version that varies between different VISTA P-Series Panels. These firmware requirements are listed below.

  • VISTA 10P - Revision 2.0 or Higher
  • VISTA-15P & 20P - Revision 5.2 or Higher
  • VISTA-21iP - Revision 3.1 or Higher

The Firmware Version can be determined by checking the system's PROM Chip. You can identify the PROM Chip as a small, square, black chip found on the main system circuit board. The PROM Chip will have a white sticker with a code that starts with "WA". You can use this code to determine if the system is capable of supporting an SEM device like the ADC-SEM300-VT-AT. Additionally, many branded equivalents of Honeywell VISTA Panels can also support the SEM. An example of such a panel is the First Alert Professional FA16CPS.

Unlike previous SEM units, the new 300-Series SEMs utilize a much lower power consumption, at just 230mA maximum. These units also now have the new ability to be used without an external power supply, which was required with older modules. If you use the SEM without an external power supply, then all power will be supplied from the VISTA Alarm Panel. Alternatively, you can still use an external power supply if you do not have 230mA available from the panel, or if you just prefer to do use a setup with an external power supply.

Manufacturer's Note: If the SEM will be used on a VISTA Panel with a Voice Keypad, such as the 6150V, 6160V, etc., then be sure that the SEM is on Version 1.60+.

Certain peripherals are not compatible with the ADC-SEM300-VT-AT. Be sure that none of the following devices are being used on the panel before adding the SEM:

  • AVS (Audio Verification System)
  • Honeywell 4232CBM
  • Telephone (POTS) line for monitoring
  • Sensor Activity Monitoring (SAM) is not supported for the following device: Honeywell 5822T Tilt Sensor. If any of these devices are being used, be sure SAM is disabled for each of these sensors.


  • Product Type: System Enhancement Module (SEM) Communicator
  • Compatibility: Honeywell & ADEMCO VISTA P-Series Alarm Panels and their equivalents
  • Minimum Panel Firmware: VISTA-15P VISTA-20P Version 5.2+ ; VISTA-10P Version 2.0+ ; VISTA-21iP Version 3.1+ (Check PROM Chip)
  • Panel Connections: 4-Wire Connection w/ 2-Wire for Data & 2-Wire for Power
  • IP Communication: Wired Ethernet
  • Cellular Carrier: AT&T LTE
  • Cellular Networks: 4G LTE w/ 3G HSPA, and 2G GSM
  • Automation: Z-Wave Plus
  • Interactive Platform:
  • Over-the-Air (OTA) Updates: Yes
  • Tamper Switches: Cover and Wall Detection
  • Power Requirements: 12 V nominal, 125 mA nominal (continuous), 230 mA max
  • LED Lights: Five (5) Total
  • ETL Listings: UL985, UL1023, and ULC S545
  • Operating Temperature: 14°F to 131°F
  • Storage Temperature: -30°F to 140°F
  • Operating Humidity: 90% Relative Humidity, Non-Condensing
  • Enclosure Dimensions: 7.66"L x 4.35"W x 1.65"D
  • Enclosure Color: White
  • Case Material: Fire-retardant PC/ABS, PC

Brand: Honeywell ADC-SEM300-VT-AT Compatible Products

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