SA24M - IBIS Master

The SA24M provides one IBIS master interface with an external 24V supply. While a fieldbus master controls the data traffic, the data transfer between master and slave participants is initiated only by the master.

IBIS is a fieldbus used in public transport vehicles. It is based on a UART structure and can therefore be combined with MEN boards that support any kind of UART interfaces together with SA-Adapter slots.

SA-Adapters are small universal boards providing the physics for legacy serial I/O, fieldbus interfaces and other small I/O functions. One serial line is provided per adapter, which can be plugged directly to the CPU board as a mezzanine. Alternatively, the adapter can be connected to the front panel via ribbon cable. The SA concept allows to add additional I/O interfaces to many of MEN's CPU boards and box PCs, enhancing flexibility with regard to the line transceivers and isolation requirements. Whether a specific SA-Adapter (or a mix of different SA-Adapters) fits on a specific CPU board is determined by a combination of mechanical, performance, FPGA and operating system criteria and needs to be verified for every board configuration requested.


  • 1 channel master
  • Over-current and short-cut protection
  • Optical isolation
  • -40 °C to +85 °C


  • IBIS master on front connector
    • External 24V power supply on front connector for IBIS signal level
    • Standard IBIS data rate (1200 bit/s) up to standard UART data rate (up to 9600 bit/s)
  • Serial TTL Interface on 10-pin SA-Adapter connector
  • As a piggy-back board directly on a carrier board
  • Via ribbon cable
Peripheral Connections
Via front panel on a shielded 9-pin D-Sub receptacle connector
Electrical Specifications
  • Isolation voltage:
    • 750V DC or 500V AC between isolated side and digital side
  • Supply voltage/power consumption:
    • Digital side +5V (-3%/+5%), 10 mA typ. (25 mA max.)
    • Isolated side +24V (-30%/+25%), 10mA typ. (110 mA max., when loopback on pin 1/2)
  • MTBF: tbd @ 40°C according to IEC/TR 62380 (RDF 2000)
Mechanical Specifications
  • Dimensions: 32mm x 42mm
  • Weight:
    • 18g (Master)
Environmental Specifications
  • Temperature range (operation):
    • -40..+85°C
  • Temperature range (storage): -40..+85°C
  • Relative humidity (operation): max. 95% non-condensing
  • Relative humidity (storage): max. 95% non-condensing
  • Altitude: -300m to + 3,000m
  • Shock:
    • 50 m/s², 30 ms (EN 61373)
    • 15 g, 11 ms (EN 60068-2-27)
  • Vibration (function): 2.02 m/s², 5 Hz to 150 Hz (EN 61373)
  • Vibration (lifetime): 11.44 m/s², 5 Hz to 150 Hz (EN 61373)
  • Conformal coating
Flammability (PCBs)
  • UL 94 V-0
  • EN 50121-3-2 (conducted disturbance)
  • IEC 61000-4-4 (burst)
  • IEC 61000-4-6 (conducted disturbances)