Sentry IT Retrofit Upgrade

Modernize Your Facility's Infrastructure

Sierra Monitor's Sentry gas detection solutions have long been the technology of choice for facility managers. With a reputation for innovation and reliability, Sentry solutions have been installed in tens of thousands of facilities that face potential risks from combustible and toxic gases.

However, the diligent facility manager knows that to stay “state-of-the-art," they must periodically refresh the technology deployed on site. New advances in sensing algorithms, protocols, web technologies, and cloud connectivity have the potential to enhance safety, reduce ongoing operational costs, and provide new big-data driven insights.

Many facility managers are upgrading to Sierra Monitor's Sentry IT solution to take advantage of newer technology. Our Retrofit Kit makes it easy to upgrade from currently installed “Classic" Sentry installations to the state-of-the-art Sentry IT, while still preserving the majority of the facility's investments in gas detection modules.

Learn more about the Sentry IT Controller »

Learn more about how Sentry IT works with the FieldPoP device cloud »

Sentry IT Retrofit Upgrade

  • Keep installed detector modules - no need for new wires
  • More channels - additional input and output capacity
  • Web and cloud enabled for easy-to-access and easy-to-view dashboards and reports
  • Easy interface to virtually any SCADA or Building Management System - included in the basic product
  • Minimal downtime - keep your plant operational

Specifications for Sentry IT Retrofit


  • AC Version: 120/240 VAC +/- 10%, 50/60 Hz
  • DC Version: 24 VDC Nominal (18-30 VDC)
  • Power consumption: Controller 50W, Typical max system 200W
  • Battery Backup capability: External option


  • Operating Temperature: -14°F to 131°F (-10°C to 55°C)
  • Storage Temperature: -4°F to 140°F (-20°C to 60°C)
  • Relative Humidity: 0-95% Non-condensing


  • Type: 5.7" color, backlit touch-screen
  • Environmental rating: NEMA 4
  • Views: Bar charts, text data screens, configuration screens
  • Other Indicators: Integral long-life, high-intensity LED lights for Safe, Warning, Alarm, and Trouble

Connectivity to external controls and systems

  • Controller to Ethernet: Modbus TCP or AllenBradley Ethernet/IP (other protocols available)
  • Optional - Remote management: Web browser interface
  • Optional - Mass storage: Flash drive via USB port

Connectivity to modules

  • Channels: Up to 32 module addresses
  • Channel power: 24 VDC
  • Communication:
    • Analong 4-20 mA: 2, 3, or 4-wire per ISA specifications
    • Modbus RTU (Sentry IT): RS-485 (half-duplex)
      • Baud: 38400 baud (adjustable 2400 - 38400)
      • Parity: None
      • Stop bit: 1
      • Data bits: 8
      • Flow control: None
    • SentryBus: Proprietary Power, Signal, Ground (PSG)
    • Binary Input: Supervised or Digital Input


  • 4-20 mA: Variable retransmission 3-wire or 4-wire
  • Relay: Programmable, SPDT (multiples of 8)
  • Standard: 5 Amps
  • Optional: 8 Amps
  • Trouble: 5 Amps, Fail-safe


  • Design: Wall-mount


  • 2 years

How It Works

The Sentry IT Retrofit solution to replace a classic Sentry controller with a Sentry IT controller is intended for existing installations only. The standard Sentry IT controller would be ordered if there is nothing to replace on site.

Retrofit Kits are available for the Single Sentry Controller NEMA, Dual Sentry Controller NEMA, and Rack Chassis. There is no Retrofit Kit for the Sentry EXP NEMA 7 enclosure. Each Retrofit Kit has different materials associated with it. Although mounting, installation, and wiring are different depending on which style is selected, the kit contains all the necessary hardware to mount all the new equipment.

How to Purchase the Sentry IT Retrofit Upgrade

Find Your Local Sales Partner

We work with a variety of sales partners around the world to increase our ability to reach customers. If you are looking to purchase the Sentry IT Retrofit upgrade, please contact the sales partner that covers your location:

Contact Us

You can directly contact us to receive a quote: