PARAMETERIZABLE Special Module (PSM), Function - GF54.21-D-0002H

MODEL 906 with CODE (ED5) Parameterizable special module (PSM) 

MODEL 906 with CODE (ED8) Preinstallation for parameterizable special module (PSM) 

Courtesy of MERCEDES-BENZ USA

Connection, shown on model 906 with code (ED5) Parameterizable special module (PSM) 

The PSM control unit forms the interface between the vehicle and the body manufacturer electronics.

Thanks to the body manufacturer electronics vehicle information can be read in by means of the PSM control unit via the Controller Area Network bus class B (interior) (CAN-B) and vehicle functions controlled (e.g. the central locking system (CL)).

For this there are digital and analog inputs and outputs (10 discrete inputs and 20 discrete outputs; the latter can likewise be used as inputs). For complex bodies, which require more inputs or outputs, the Controller Area Network-Bus Class C (body manufacturer) (body manufacturer CAN) is available as a further interface. A multitude of vehicle signals are transmitted on this. In addition there are some "free messages" which can be freely assigned with arbitrary contents.

The PSM control unit can thus convert information, which it receives via Controller Area Network (data bus/CAN bus) (CAN) messages, to discrete outputs or the body manufacturer CAN. In exactly the same way the PSM control unit can pass on discrete inputs or information from body manufacturer CAN to CAN B.

Over and above the interfaces internal functional units are available in the PSM control unit, e.g.:

• Access to motor functions (working speed control, engine start/stop)
• Programmable logic controller (PLC) functionality (logic operations AND, OR etc. of signals)
• Undervoltage detection

The type and direction of information and interfaces with the aid of STAR DIAGNOSIS. Only through this parameterization is the usability of the PSM control unit established and adapted to the corresponding body. For SA codes available from the plant, parameterization of the PSM control unit can be performed at the touch of a button via the menu standard coding. Parameterization via the expert coding is required for all other adjustments.

The SA codes available from the plant are:

• Retarder with code (BR9) Preinstallation for Telma retarder
• Working speed control:
  • with code (MT4) Electronic variable rpm regulator
  • with code (MT4) Electronic variable rpm regulator and with code (N05) Power take-off countershaft (2c) without flange
  • with code (MT4) Electronic variable rpm regulator and with code (N07) Power take-off countershaft (2b) with flange
  • with code (M53) Constant rpm control
  • with code (M53) Constant rpm control and with code (N05) Power take-off countershaft (2c) without flange
  • with code (M53) Constant rpm control and with code (N07) Power take-off countershaft (2b) with flange
• Preinstallation for crash data recorder with code (JV5)