MTL 5514 HART Isolator | 2-Ch, 4-20mA with HART, IS, DIN Rail, ATEX/IECEx/FM Specs

MTL 5514 HART Isolator | 2-Ch, 4-20mA with HART, IS, DIN Rail, ATEX/IECEx/FM Specs

MTL 5514 dual-channel HART analog isolator specifications. Two 4-20mA+HART inputs/outputs, galvanic isolation, 24V DC, DIN rail. ATEX/IECEx/FM certified for hazardous areas.

Product Overview

The MTL 5514​ is a dual-channel, programmable analog isolator​ from MTL's 5500 series, specifically designed to support the HART communication protocol. It accepts a 4-20mA signal with superimposed HART digital data​ from a smart field instrument in a hazardous area, provides intrinsic safety (IS) isolation and signal conditioning, and delivers a replicated, isolated 4-20mA+HART output​ to the safe area. It enables bidirectional HART communication through the isolator, allowing a HART master (e.g., a control system, handheld communicator, or asset management software) in the safe area to configure, monitor, and diagnose smart field devices in the hazardous area.

Technical Specifications

Note: Specifications are based on MTL 5500 series documentation. The 5514 is software-configurable. Always verify with the latest product datasheet.

Key Features

• HART Protocol Support:​ Bidirectional pass-through of HART digital signals, enabling communication with smart field devices (e.g., pressure, temperature, level transmitters) through the isolator.

• Dual Independent Channels:​ Two fully isolated HART channels in a compact 12.5mm module.

• High Analog Accuracy:​ ±0.05% accuracy ensures precise analog signal transmission alongside HART data.

• Complete Isolation:​ 500V galvanic isolation between hazardous and safe areas, and between channels, preventing ground loops and protecting systems.

• Intrinsic Safety:​ Certified for Zone 1/21, allowing direct connection to HART field devices in explosive atmospheres.

• Transparent Operation:​ Does not require HART addressing or configuration itself; it acts as a signal conditioner and isolator, passing HART data unchanged.

• Low Signal Distortion:​ Maintains HART signal integrity with minimal attenuation and phase shift.

• Visual Diagnostics:​ Per-channel LEDs indicate power status and HART communication activity.

• Flexible Configuration:​ Software allows configuration of fail-safe modes, damping, and other parameters.

How It Works: HART Signal Path

The MTL 5514 separates and recombines the analog and HART signals:

1. Input Side (Hazardous Area):​ Receives the combined 4-20mA analog + HART FSK signal from the smart transmitter.

2. Signal Processing:​

   • The analog 4-20mA component is isolated, conditioned, and replicated.

   • The HART AC component (~1mA p-p) is isolated, amplified, and re-injected.

3. Output Side (Safe Area):​ Delivers a regenerated, isolated 4-20mA + HART signal that is functionally identical to the input.

This allows a HART master connected on the safe side to communicate with the field device as if the isolator were not present.

Wiring Configuration

Typical Connection for a 2-Wire HART Transmitter:

[Hazardous Area]                 [Safe Area]
                                   +24V PSU
                                        |
Smart HART                           |  |
Transmitter (+) ---- Ch1 IN+  MTL    |  |
                 |              5514 |  |    HART Master
                 |               |    |  |   (e.g., Handheld)
Smart HART       |               |    |  |       ||
Transmitter (-) ---- Ch1 IN-  |  |    |  |       ||
                 |            |  |    |  |       /
[IS 24V +]-------+------------|--|----+  |  [PLC AI Card + HART]
                               |  |      |       ||
                               |  | Ch1 OUT+ -----+
                               |  | Ch1 OUT- -----+

Note: The HART master can be connected across the output loop terminals (OUT+ and OUT-), typically in parallel with the PLC's analog input. The isolator's 250Ω input resistor provides the necessary load for HART communication.

Entity Parameters (for Hazardous Area Loop Design) - Per Channel

The connected HART field device must be IS certified. The total capacitance and inductance of the field device and field wiring must be within the allowed values.

Configuration & Software

The MTL 5514 is configured using the MTL Software Suite​ (or similar) and a USB programming cable. While it is transparent to HART data, configuration is needed for:

• Fail-Safe Mode:​ Defining the output analog value (e.g., hold last, upscale, downscale) on input signal loss or power failure.

• Damping/Filtering:​ Applying smoothing to the analog output signal.

• Status Alarms:​ Configuring response to fault conditions.

• Basic calibration.

Typical Applications

• Smart Instrumentation Integration:​ Isolating and conditioning signals from HART-enabled pressure, temperature, level, and flow transmitters in hazardous areas.

• Online Device Diagnostics & Configuration:​ Enabling a HART handheld communicator or asset management system in the control room to communicate with field devices for configuration, calibration, and diagnostics.

• Multidrop HART Networks:​ Supporting multidrop HART networks (where multiple devices share a loop) with isolation, though loop power requirements must be carefully considered.

• Legacy System Upgrades:​ Adding HART communication capability to existing DCS/PLC systems that have HART-capable I/O or modems.

• SIL Applications:​ Providing isolated, HART-compatible signal paths for safety instrumented loops.

Important Technical Notes

1. HART Load Resistor:​ The MTL 5514 incorporates a 250 Ω input impedance, which is the required load for HART communication. No additional resistor is needed​ in the loop. The output loop must have a total resistance between 230-600 Ω for reliable HART communication.

2. Loop Power & Voltage Compliance:​ The field device (transmitter) requires an IS 24V DC power supply. The total loop resistance (field device + isolator input + wiring) must be within the compliance voltage of the IS power supply. The output side also requires a 24V DC supply​ for the analog loop.

3. Software Configuration Required:​ The unit requires initial configuration via PC software. It is not plug-and-play for analog parameters.

4. Transparency:​ The 5514 is a Layer 1 (physical layer) device. It does not interpret HART commands; it simply passes the modulated signal. HART addressing and configuration are done with the field device directly.

5. Multidrop Consideration:​ In a multidrop network, the current draw of multiple devices plus the isolator's input impedance must be calculated to ensure sufficient loop voltage.

6. Wiring Practices:​ Use single twisted-pair cable​ for HART. Avoid parallel runs with power cables. Follow HART installation guidelines for optimal communication.

7. LED Indicators:​ A yellow LED flashes to indicate HART communication activity on that channel.

Note: This data sheet provides general specifications for the MTL 5514 HART analog isolator. For complete installation instructions, wiring diagrams, software configuration guide, HART network design, intrinsic safety guidelines, and certification details, consult the official MTL 5500 Series Technical Manual​ and the product-specific data sheet. Programming software and cable are required for setup.

More Products

Pepperl Fuchs Safety Barrier

Allen Bradley PLC Controllers

SICK Instruments 

Festo Cylinder 

IFM Sensors 

About ACH

Founded in 2012, ACH is a top-tier distributor of industrial automation products, supplying genuine devices from leading brands like ABB, P+F, E&H, AB, MTL and EMERSON to emerging markets worldwide. Our mission is to provide 100% Genuine products at the most competitive prices, helping customers reduce costs and strengthen their market position.

Frequently Ask & Questions

Are preferential prices available?

Long-term brand partners can get competitive product prices. At the same time, ACH controls the profit per order to 5%, providing the most competitive prices.

Are the Products Genuine OEM Units?

Yes, all products from ACH are certified genuine OEM units. We acquire our inventory through official OEM channels and trusted third-party suppliers, ensuring every item is authentic and reliable.

How will you arrange shipment?

We'll handle the shipping for you. Through our partnerships, we can secure competitive rates with major carriers like FedEx, DHL, TNT, and UPS, ensuring a smooth and cost-effective delivery.

What is the warranty of goods?

One-year Warranty.

How long is the logistics cycle of the product?

Products are divided into spot and futures, and the delivery period of different brands of products is also different. For details, please contact the ACH business manager.