Siemens HTRI-D Dual Input Interface Module P/N:500-033360

The Siemens HTRI-D Dual Input Interface Module P/N: 500-033360 is an intelligent addressable interface device designed for compatible Siemens fire alarm systems. It provides two independently monitored dry-contact inputs, allowing two initiating or supervisory devices to connect to the addressable device loop through a single module.

The HTRI-D incorporates onboard microprocessor technology and bi-directional communication with the fire alarm control panel. Both inputs share a single module address while maintaining independent input response.

Product Functions

• Provides two supervised inputs
• Monitors two independent dry-contact circuits
• Uses one intelligent device address
• Provides independent response from each input
• Supports normally open contacts
• Supports normally closed contacts
• Uses polarity-insensitive two-wire operation
• Provides dynamic circuit supervision
• Uses onboard microprocessor technology
• Provides bi-directional panel communication
• Supports electronic address programming
• Provides multi-color LED indication
• Designed for compatible Siemens fire alarm systems

Dual Input Operation

The HTRI-D provides two independently monitored inputs:

Input 1

Input 2

Each input can monitor a separate dry-contact device while the HTRI-D communicates both conditions to the compatible Siemens fire alarm control panel.

This allows two related initiating or supervisory devices to be monitored using a single interface module.

Single Address Operation

A key feature of the HTRI-D is that both monitored inputs operate through:

One device address

Even though the module occupies a single address, the two inputs can respond independently.

This reduces address usage compared with dual-input devices requiring a separate loop address for each monitored circuit.

Dry Contact Monitoring

The HTRI-D is designed to interface direct-shorting dry-contact devices with the addressable fire alarm loop.

Typical connected equipment can include:

• Waterflow switches
• Valve supervisory switches
• Pressure switches
• Conventional initiating devices
• Equipment status contacts
• Other compatible dry-contact devices

A common application is monitoring a waterflow switch and its associated valve supervisory switch with one HTRI-D.

Intelligent Communication

The HTRI-D contains an onboard microcomputer that provides intelligent, bi-directional communication with compatible Siemens fire alarm equipment.

The module supervises its connected circuits and reports status changes to the control panel, allowing the system to apply the programmed alarm, supervisory, or other response.

Polarity-Insensitive Operation

The HTRI-D uses Siemens SureWire technology for polarity-insensitive loop connections.

This two-wire architecture simplifies field wiring by reducing polarity-related installation issues at the module.

Unlike the newer XTRI-D, the HTRI-D does not incorporate dual built-in Class X isolators.

Electronic Address Programming

The HTRI-D uses electronic addressing rather than mechanical rotary or DIP switches.

Address programming is performed using compatible Siemens programming equipment such as the:

DPU — Device Programming Unit

The programmed address is stored electronically within the module.

Multi-Color LED

The HTRI-D incorporates a multi-color status LED.

Available indication colors include:

Green

Amber

Red

The LED provides local visual indication of module communication and monitored input conditions according to the connected Siemens system.

HTRI-D vs. XTRI-D

The HTRI-D is the earlier-generation Siemens dual-input interface module.

HTRI-D: Dual input, single address, polarity-insensitive operation

XTRI-D: Newer dual-input interface with integrated dual isolators

The XTRI-D is commonly identified as the successor to the HTRI-D. Compatibility with the existing control panel and device loop should be confirmed before substitution.

Electrical & Interface Information

Model: HTRI-D

Part Number: 500-033360

Device Type: Intelligent Dual Input Interface Module

Inputs: Two

Addresses Required: One

Input Type: Supervised Dry Contact

Current Draw: 1.3 mA active or standby

Operation: Two-wire

Wiring: Polarity Insensitive

Programming: Electronic

Status Indicator: Multi-color LED

Operating Temperature: 32°F to 120°F / 0°C to 49°C

Relative Humidity: Up to 93%, non-condensing

The HTRI-D is a legacy Siemens module and has been superseded in current applications by newer interface-module technology.

HTRI-D Datasheet