Fire-Lite MDF-300 Dual Monitor Module

The Fire-Lite MDF-300 Dual Monitor Module is an intelligent addressable interface module designed for compatible Fire-Lite fire alarm control panels. It provides two independently monitored initiating device circuits (IDCs) for connecting conventional normally open contact devices to an addressable signaling line circuit.

The MDF-300 is useful where two conventional initiating or supervisory circuits are located near each other, reducing the number of individual monitor modules required.

Product Functions

• Provides two independently monitored inputs
• Intelligent addressable monitor module
• Supports Class B initiating device circuits
• Monitors normally open contact devices
• Provides individual status reporting for both inputs
• Uses rotary decimal address switches
• Supports LiteSpeed communication
• Provides LED status indication
• Supervises field wiring for open-circuit conditions
• Supports compatible end-of-line resistors
• Powered directly from the SLC
• Requires no separate external power
• Designed for compatible Fire-Lite addressable systems

Dual Input Monitoring

The MDF-300 provides:

Monitor Input 1

Monitor Input 2

Each input functions as an independently supervised Class B initiating device circuit.

This allows two conventional contact devices or circuits to connect to the addressable system through a single module.

Conventional Device Monitoring

The MDF-300 is designed to monitor normally open dry-contact initiating devices.

Typical applications can include:

• Manual pull stations
• Waterflow switches
• Valve supervisory switches
• Pressure switches
• Conventional heat detectors
• Equipment status contacts
• Other compatible normally open contact devices

The fire alarm control panel determines whether each monitored input functions as alarm, supervisory, or another programmed point type.

Addressable Operation

The MDF-300 communicates with the compatible Fire-Lite control panel through the signaling line circuit.

The module uses rotary decimal switches for address selection, simplifying device addressing and field servicing.

Each monitored input can be individually identified by the control system, allowing separate point descriptions and event reporting.

LiteSpeed Communication

The MDF-300 supports Fire-Lite’s LiteSpeed protocol on compatible signaling line circuits.

LiteSpeed communication allows rapid polling and identification of intelligent field devices while maintaining individual addressable point reporting.

Exact compatibility depends on the Fire-Lite control panel and system configuration.

Class B Circuit Supervision

Both MDF-300 input circuits operate as:

Class B IDCs

The field wiring is supervised using an end-of-line resistor installed at the end of each monitored circuit.

This allows the module and control panel to distinguish between normal, active, and open-circuit conditions.

LED Status Indication

The MDF-300 incorporates status LEDs that provide local indication of module communication and monitored circuit activity.

LED behavior is controlled by the compatible Fire-Lite fire alarm system and can provide visual confirmation during commissioning, troubleshooting, and testing.

SLC-Powered Operation

The MDF-300 receives its operating power directly from the compatible signaling line circuit.

Separate External Power: Not required

This simplifies wiring because the module does not require an additional 24V auxiliary power connection for normal monitoring operation.

Electrical & Interface Information

Model: MDF-300

Device Type: Intelligent Dual Monitor Module

Inputs: Two

Circuit Type: Class B

Monitored Devices: Normally Open Contacts

Communication: LiteSpeed

Addressing: Rotary Decimal Switches

Operating Voltage: 15–32 VDC

Maximum SLC Current: Approximately 750 µA

External Power: Not Required

Field Wiring: Supervised

Mounting: 4-inch square electrical box

Exact electrical requirements and end-of-line resistance should follow the applicable Fire-Lite technical documentation and control-panel compatibility requirements.

MDF-300 Datasheet