MTL MTL5544D Repeater Power Supply

The MTL MTL5544D is a single-channel repeater power supply designed to interface 4-20 mA field transmitters with control and monitoring equipment in the safe area while providing galvanic isolation and intrinsic safety signal transfer. The module supports both 2-wire and 3-wire transmitters, passes bi-directional HART communication, and delivers two replicated current outputs for connection to separate control system loads.

Signal Interface Functions

The MTL5544D accepts signals from a single field transmitter and transfers the process current signal to two independent safe-area outputs. This arrangement allows one transmitter signal to be shared by multiple receiving devices without requiring additional signal-splitting hardware.

The module supports standard 4-20 mA instrumentation loops and can be used with either 2-wire or 3-wire transmitter configurations.

Dual Output Capability

The output stage provides two replicated safe-area current outputs. Each output can drive loads from 0 Ohm to 450 Ohm at 20 mA, enabling connection to PLC analog inputs, DCS analog input channels, recorders, indicators, or other monitoring equipment.

The duplicated outputs allow process signals to be distributed to separate systems while maintaining isolation from the hazardous-area field circuit.

HART Communication Support

The MTL5544D supports bi-directional HART communication for compatible 2-wire HART transmitters. This allows device configuration, diagnostics, and digital communication to coexist with the analog 4-20 mA measurement signal.

Preserving HART functionality enables maintenance personnel to access transmitter information without disconnecting the measurement loop.

Power and Installation

The module operates from a 20 VDC to 35 VDC power supply and draws a maximum current of 96 mA at 24 VDC. Typical power consumption is approximately 1.4 W.

Installation is on a standard 35 mm DIN rail, making the module suitable for control cabinet mounting alongside other signal-conditioning and interface devices.

Functional Safety

The MTL5544D is suitable for use in functional safety applications. The module is certified for SIL 2 operation in single-channel applications and can be used in SIL 3 architectures when installed in appropriate redundant configurations.

These ratings make the module suitable for integration into safety-related instrumented systems where certified signal isolation and transmission are required.

Technical Specifications

Application Considerations

The MTL5544D is intended for analog process instrumentation loops requiring intrinsic safety isolation and signal duplication. It is particularly useful when a single field transmitter must provide data to multiple receiving systems while retaining HART communication capability.

When designing the loop, users should verify transmitter voltage requirements, output load resistance, and overall loop power budget to ensure proper operation.

Frequently Asked Questions

Q: How many transmitters can the MTL5544D support?

A: The MTL5544D is a single-channel device designed to interface with one 2-wire or 3-wire 4-20 mA transmitter per module.

Q: Can both output channels be used simultaneously?

A: Yes. The module provides two replicated safe-area current outputs, allowing the same process signal to be connected to two independent receiving loads.

Q: Is HART communication maintained through the isolator?

A: Yes. The MTL5544D supports bi-directional HART communication for compatible 2-wire HART transmitters while simultaneously transmitting the analog 4-20 mA signal.