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Parameterizable Special Module (PSM) Control Unit, Component Description - GF54.21-S-5005TRA

Model 447 

With Code ED5 (Parameterisable special module) 

Except Code XM7 (MOPF II) 

Model 448 

With Code ED5 (Parameterisable special module) 

Except Code XM7 (MOPF II) 

Fig 1: Parameterizable Special Module (PSM) Control Unit Components Location - Model 447 With Code ED5 Except Code XM7 (Shown On Model 447.8)
G16501321Courtesy of MERCEDES-BENZ USA

Illustration shows model 447.8 

Location 

The parameterizable special module (PSM) control unit (N26/16) is located under the left front seat.

Tasks 

The CAN connection of the parameterizable special module can be configured such that it functions as a body manufacturer CAN (CAN ABH) or as a peripheral device CAN. With 125 kBd, it is also possible to configure the body manufacturer CAN (CAN ABH) and the peripheral device CAN at the same time.

IMPORTANT The CAN in Automation (CiA) standardization committee originally defined a CAN-based protocol standard for automation technology, the so-called CANopen protocol. Today, there are dedicated standards for various applications. The peripheral device CAN complies with the CiA standard CiA 447-3 and is a CAN-based communication system. It consists of protocols and profile specifications and was developed as a standardized network with highly flexible configuration functions.

The parameterizable special module (PSM) control unit (N26/16) is responsible for the following tasks:

Reading in of signals 

Signals are read in via the following connections:

Direct line 

The signals from the following component parts are read via direct line:

Interior CAN (CAN B) 

The signals of the other component parts connected to the interior CAN (CAN B) are read in. The resultant functions are described in the respective function descriptions.

Peripheral device CAN 

The signals of the other component parts connected to the peripheral device CAN are read in. The resultant functions are described in the respective function descriptions.

Body manufacturer CAN (CAN ABH) 

The signals are sent via the body manufacturer CAN (CAN ABH) to the other component parts connected to the body manufacturer CAN (CAN ABH). The resultant functions are described in the respective function descriptions.

Evaluation of signals 

The signals that have been read in are evaluated by the integrated microprocessor and the corresponding component parts are then actuated.

Actuation of component parts 

The actuation of the component parts takes place via the following connections:

Direct line 

The following component parts are actuated via a direct line:

Interior CAN (CAN B) 

The signals are sent via the interior CAN (CAN B) to the other component parts connected to the interior CAN (CAN B). The resultant functions are described in the respective function descriptions.

Peripheral device CAN 

The signals are sent via the peripheral device CAN to the other component parts connected to the peripheral device CAN. The resultant functions are described in the respective function descriptions.

Body manufacturer CAN (CAN ABH) 

The signals are sent via the body manufacturer CAN (CAN ABH) to the other component parts connected to the body manufacturer CAN (CAN ABH). The resultant functions are described in the respective function descriptions.

  Wiring diagram for parameterizable special module (PSM) control unit Model 448 with code ED5 (Parameterizable special module) PE54.21-S-2500-97VDA
    Model 447.6/7 with code ED5 (Parameterizable special module) PE54.21-S-2500-97VVA
    Model 447.8 with code ED5 (Parameterizable special module) PE54.21-S-2500-97VVB