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MEN Mikro K4 - 4 Safe Frequency Inputs

MTCS Safe I/O Board SIL 2 to SIL 4

MEN Mikro K4 - 4 Safe Frequency Inputs
Key Features
MTCS I/O board using ETG.1000
Four frequency inputs, four signals each
Quad encoded signal input, 0.1 Hz to 30 kHz
Voltage supply of connected sensors
Extensive supervision functions
Full EN 50155 compliance
Certifiable up to SIL 4
-40 to +85°C with qualified components


The K4 is a safe frequency input card for use in an MEN Modular Train Control System. MTCS is a platform to perform safe train control functions, focusing on rolling stock applications like Automated Train Operation (ATO) or Automated Train Protection (ATP). It usually consists of the MH50C MTCS controller system and safe remote I/O boxes, e.g., KT8. The K4 can be a part in any of these systems, with one card providing four frequency inputs.

Safe, Certified Railway I/O

Developed according to EN 50129/EN 50128, K4 boards can be used for SIL 1, SIL 2, SIL 3 and SIL 4 applications. All MTCS I/O components come with dedicated SIL 4 certification packages from TÜV SÜD, reducing the integrator's certification effort and risk, and resulting in lower integration costs.

Functional Safety Design

With a dedicated onboard supervisor and FSoE features (Fail Safe over Ethernet), the I/O board is equipped with all the mechanisms required to provide protection in functionally safe systems. The I/O card reacts to be fail-safe: it enters the safe state if it detects an error.

In-System Connection using Real-Time Ethernet

MTCS I/O boards are physically shorter than a 3U CompactPCI board. Inside an MTCS system, these cards connect to the backplane using an extension. This links them to the MTCS EBUS, power supply, and address lines, allowing safe real-time Ethernet communication within the system. Front I/O is connected via spring cage terminal blocks for fast installation thanks to reduced wiring.

EN 50155 Rolling Stock Compliance

The K4 can supply the connected sensors and tolerates the voltage ranges defined by EN 50155 for railway applications. Being usable in all types of different trains optimizes the I/O board's interoperability. Its operating temperature complies with the class TX specifications of -40 to +70 °C (10 minutes up to +85 °C). Standard boards include conformal coating. Along with its full EN 50155 compliance and long-term availability of a minimum 10 years, the K4 is a rail-ready I/O component.

Safe Software Concept

All MTCS components are supported by certified QNX BSP and driver software.



FeaturesFour frequency inputs, four signals each
Quadrature encoded signal input, 0.1 Hz to 30 kHz
Voltage supply of connected sensors
Optical isolation from other cards

Status LEDs
• Binary channel status, one LED per channel
• I/O error
• FSoE activity
• Real-time Ethernet error
• Real-time Ethernet state indication

Safe supervisor
• Check for overvoltage, undervoltage, excess temperature
• Watchdog
• Monitor self-test
ConnectionsOne spring cage terminal block


ExpansionEBUS: Two real-time Ethernet channels, ETG.1000
MTCS FSoE: Slot ID and chassis ID for unique FSoE address
Backplane Standard: ETG.1000 EBUS
ElectricalSupply voltage: +12 V (10.8 to 13.2 V)
Power consumption: tbd. W
Isolation voltage: 1500 V AC
Mechanical100 mm x 100 mm, 4 HP
Conformal CoatingConformal coating (standard)
SoftwarePACY (Process Data Framework for Cyclic Applications)
TemperatureTemperature range (operation):
• -40 to +85°C (qualified components)
• EN 50155, class TX)
Temperature range (storage): -40 to +85°C
Cooling concept: Air-cooled, natural convection
HumidityEN 50155: Rolling stock, vehicle body
Altitude-300 m to +3000 m
VibrationEN 50155: Rolling stock, vehicle body class B
ShockEN 50155: Rolling stock, vehicle body class B
Safety/CertificationFlammability: UL 94V-0
Fire Protection: EN 45545

Functional Safety
• Certifiable up to SIL 4 according to EN 50129 ("safety case" document and certificate from TÜV SÜD)
• Hazard rate (THR) for safety functions <= 1E-8 / h
• Board maintains safe state after a failure
EMCEN 50155: Rolling stock, vehicle body
Warranty2 Years

Ordering Details

4 frequency inputs, SIL 2 (SIL 4), -40 to +85C qualified, conformal coating
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