Description
Product Introduction
Unstable sensor readings or missing process values can complicate fault diagnosis aboard a vessel, particularly when several field signals share a common automation platform. The STN Atlas MXM402, part number 271.130 442, is a marine automation interface expansion module designed to acquire analog signals from connected field devices. Its documented configuration provides 16 inputs and allows additional compatible input modules to be connected.
For maintenance engineers, the key is to match the module’s input type, wiring, and expansion arrangement to the installed system. The MXM402 supports voltage, current, and PT100 resistance-temperature measurements. Before purchasing a replacement, confirm the complete part-number suffix, supply requirements, and existing configuration—especially when working with legacy STN Atlas or Lyngsø Marine equipment.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Model | MXM402 |
| Part Number | 271.130 442 |
| Related Manufacturer Part Number | 962.004.300 |
| Manufacturer / Brand | STN Systemtechnik Nord / STN Atlas; associated with Lyngsø Marine |
| Product Type | Analog input interface expansion module |
| Analog Input Count | 16 |
| Voltage Input | Up to 10 V; input resistance approximately 10 MΩ |
| Current Input | 0–20 mA; input resistance approximately 75 Ω |
| Temperature / Resistance Input | PT100 and resistance measurement, subject to configuration |
| Resistance Measurement | Up to approximately 2 kΩ |
| Resistance Measurement Excitation | Adjustable current pulse; documented options include 20 mA, 10 mA, and a lower-current setting |
| Expansion Capacity | Up to five additional compatible input modules |
| Expansion Interface | X10 |
| Power Supply | 5 V DC via connector X9 |
| Current Consumption | Approximately 90 mA |
| Dimensions | Approximately 125.4 × 216 × 68 mm |
| Mounting | DIN-standard support rail |
| Operating Temperature | 0°C to +55°C |
| Weight | Approximately 550 g |
| Environmental / Marine Approvals | The specification lists ABS, DNV, GL, LR, RINA, KR, and MRS approvals; verify applicability to the exact revision |
Technical note: The temperature range and resistance-measurement details should be checked against the original manual for the specific revision before engineering use. The 5 V supply is the module’s documented supply requirement; do not connect an external supply until the host-system wiring has been verified.
MXM402-271.-130-442
Application Scenarios & Pain Points
Marine monitoring systems depend on accurate field signals. A wiring mismatch or incorrectly configured input can look like a failed sensor, even when the actual issue is in the interface module or its expansion arrangement.
- Engine-room monitoring: Acquire compatible analog measurements from temperature and other process sensors.
- Marine automation panels: Expand analog input capacity where supported by the existing control system.
- Legacy vessel maintenance: Replace a faulty MXM402 while preserving the established sensor wiring and system architecture.
- Fault diagnosis: Isolate signal-acquisition issues by checking the sensor, field wiring, module input, and controller indication in sequence.
Field note: If several readings fail at the same time, investigate the module supply, shared wiring, and expansion connection before replacing individual sensors. If only one channel is affected, inspect its field circuit and input configuration first.
Related Products
The following modules are associated with the broader STN Atlas / Lyngsø Marine automation family. Their functions differ, so they are not confirmed drop-in replacements for MXM402.
- MXM401 — Multiplexer Module: Related module in the same equipment family; confirm input architecture and system compatibility before substitution.
- AEM402 — Analog Input Module: Analog signal acquisition module identified in related STN Atlas / Lyngsø Marine listings.
- DEM401 — Digital Input Module: Intended for digital input signals rather than the MXM402’s analog measurements.
- DRM401 — Digital Relay Module: Used for relay-related functions; not an analog input substitute.
- ZM401 — Central Module: Central system module in the related STN Systemtechnik family.
- SIM401 — Dual Serial Interface Module: Serial-interface function for compatible systems; does not replace analog acquisition hardware.
Engineer’s Guide: Field Pitfalls to Avoid
1. Confusing the with the MXM401
The two model numbers are similar, but that does not establish electrical or functional interchangeability.
Avoid it: Confirm the complete model and suffix on the installed unit. Match the module against the system’s parts list and wiring documentation before ordering.
2. Applying the wrong supply or signal wiring
The specification describes a 5 V DC module supply through X9, with expansion through X10. Incorrectly applying an external supply or wiring a current signal as a voltage input may damage equipment or produce invalid readings.
Avoid it: Verify terminal assignments and the host-system interface before connecting power. Confirm whether each field signal is voltage, current, or PT100/resistance, and follow the specified input wiring.
3. Overlooking expansion and sensor configuration
Additional modules may be recognized by a module identifier, but that does not eliminate the need to verify the system’s configuration and channel mapping.
Avoid it: Document existing wiring and channel assignments before removal. After installation, check each channel against a known input or calibrated test source and confirm that values appear correctly in the host system.
Frequently Asked Questions
Q1: What is the STN Atlas 271.130 442 used for?
It is an analog input interface expansion module used in compatible marine automation systems. Its documented configuration provides 16 analog inputs for voltage, current, and PT100/resistance measurements.
Q2: How many analog inputs does the support?
The available specification lists 16 signal inputs. It also describes expansion by up to five additional compatible input modules. Confirm the capacity and supported combinations for the particular host system.
Q3: What power supply does the require?
The available specification states that the module receives 5 V DC through connector X9, with a current consumption of approximately 90 mA. Check the original system wiring before applying power.
Q4: Can replace MXM401?
Not automatically. Their similar names do not prove that their input capabilities, expansion interfaces, or system roles are identical. Confirm compatibility with the host system’s documentation before approving a substitution.
Q5: Are 271.130 442/B and 271.130 442/F interchangeable?
Both suffixes appear in listings for modules, but the available references do not establish that the revisions are fully interchangeable. Compare the unit label, connector arrangement, and documented hardware revision before purchasing.
Q6: What should be checked before accepting a replacement?
Verify the full part number, physical condition, connectors, supply requirements, and input specifications. Request documented testing where possible, including input-channel checks and verification in a compatible system. A visual inspection alone does not confirm functional performance.
Q7: What information should I provide when requesting a quotation?
Provide the complete model , part number 271.130 442, the full suffix if present, host-system model, required quantity, preferred condition, and delivery deadline. Request written confirmation of compatibility, stock status, testing, warranty, and return terms before ordering.
