M57 - Mezzanine Card with Profibus DP Master Interface

The M57 is a Profibus DP (Distributed Peripherals) interface. The M-Module is based on the ASPC 2 controller and the 16-MHz Motorola MC68331 CPU. It is an ideal interface solution for intelligent remote I/O applications via a very popular fieldbus standard.

The ASPC 2 is an advanced Profibus controller allowing 127 stations with 254 SAPs (Service Access Points) each. It allows data transfer rates of up to 12 Mbaud on the M57.

The mezzanine card MC68331 is a 68020-based CPU which handles communication with the host CPU via the on-board 1 MB of shared DRAM. The advantage of this Profibus application using the MC68331 is that the complete Profibus protocol stack runs locally on the M-Module with very reduced interaction of the host CPU.

The Profibus firmware consists of the true Softing protocol stack. The corresponding driver software comes from MEN and complies with the standard Softing PROFIBUS DP Configurator tool. It supports configuration of the M57 for each application in a very convenient way. The driver is based on MDIS (MEN Driver Interface System) which makes the M57 ready for use under Windows, Linux and RTOS environments.

The optically isolated RS485 Profibus interface is supplied by an on-board DC/DC converter.

The M57 is based on the M-Module ANSI mezzanine standard. It can be used as an I/O extension in any type of bus system, i.e. CPCI, VME or on any type of stand-alone SBC. Appropriate M-Module carrier cards in 3U, 6U and other formats are available from MEN or other manufacturers.


  • Class 1/2 Profibus DP master (DIN19245)
  • Isolated RS485, RS232 (debug) interface
  • Local 32-bit CPU
  • Up to 127 active or passive stations
  • 12 Mbit/s data transfer rate
  • 1 MB DRAM
  • Complete Softing Profibus software on board
  • Compatible with PROFIBUS DP Configurator


MC68331/16MHz CPU
  • CPU32 performance
  • Complete Profibus DP software on one M-Module
  • Local interrupt controller
  • Hardware watchdog
ASPC 2 Profibus Controller
  • Up to 12Mbaud data rate
  • 16-bit DMA interface (local)
  • Complete bus access protocol
  • Up to 127 active or passive stations
  • 1MB shared memory for communication and program
  • Fast M-Module interface with autoincrement address mode
  • Status LEDs
  • Isolated Profibus interface
Peripheral Connections
Via front panel on a shielded 9-pin D-Sub receptacle connector
M-Module Characteristics
A08, A24, D16, INTA, IDENT
Electrical Specifications
  • Isolation voltage: 500V DC
  • Supply voltage/power consumption: +5V (4.85V..5.25V), 800mA typ.
  • MTBF: 45,000h @ 50°C (derived from MIL-HDBK-217F)
Mechanical Specifications
  • Dimensions: conforming to M-Module Standard
  • Weight: 92g
Environmental Specifications
  • Temperature range (operation):
    • 0..+60°C
    • Industrial temperature range on request
    • Airflow: min. 10m³/h
  • Temperature range (storage): -40..+85°C
  • Relative humidity range (operation): max. 95% non-condensing
  • Relative humidity range (storage): max. 95% non-condensing
  • Altitude: -300m to + 3,000m
  • Shock: 15g/11ms
  • Bump: 10g/16ms
  • Vibration (sinusoidal): 2g/10..150Hz
  • Conformal coating on request
PCB manufactured with a flammability rating of 94V-0 by UL recognized manufacturers
Tested according to EN 55022 (radio disturbance), IEC 61000-4-2 (ESD) and IEC 61000-4-4 (burst)
Software Support
  • Softing protocol portation (ISO/OSI protocol layer 2/DP)
  • MEN Driver Interface System (MDIS for Windows, Linux, VxWorks, QNX)