The parameterizable special module (PSM) control unit (N26/16) has a second CAN bus which enables data to be exchanged in addition to the discrete inputs and outputs. The data that can be accessed over the peripheral device CAN are listed in the "CAN-Matrix" in the document "PSM CAN matrix, function".
The peripheral device CAN can be activated by a signal from the signal pool, e.g. with signal 1219, "Status of terminal 15".
Specification:
"High speed CAN Class C", "Extended CAN identifier" (29 Bit)
Baud rate switchable between 500 kBit/s, 250 kBit/s and 125 kBit/s
Signal format = Intel (Least significant bit first) (LSB)
Nominal voltage = 5 V
Transceiver = "TJA1043"
Terminating resistor of parameterizable special module (PSM) control unit = 60 Ω
All CAN content can be activated separately and independent of each other per coding.
As the peripheral device CAN is already terminated with a 60 Ω resistor in the parameterizable special module (PSM) control unit, none of the other peripheral device CAN subscribers may have additional terminating resistors (e.g. 120 Ω).
Fleet management system (FMS)
The fleet management system only contains messages to be sent by the parameterizable special module (PSM) control unit.
These messages contain the following information, for example:
Vehicle speed
Engine values
Driver information
International organization for standardization = ISO.
ISO11992-2/3
This standard contains send and receive messages. The transmit messages contain information similar to that for the fleet management system (FMS), with the addition of some items of engine information. The signals received from the parameterizable special module (PSM) control unit are stored in a signal pool and can be used, for example, for working speed control.
Freely assignable messages
The freely assignable messages are output as follows:
In the transmit direction, 4 messages ("GPM_1H", "GPM_1I", "GPM_1J", "GPM_1K")
in the receive direction, 4 messages ("GPM_2H", "GPM_2I", "GPM_2J", "GPM_2K")
The send signals are assigned from the signal pool. The receive signals are stored in the signal pool to await further use. The signals are given the designation "AuxBit, AuxByte" etc.
Details can be found in the document "PSM signal lists, function".
Activation of the freely assignable messages is only possible if the message package ISO11992-2/3 has also been activated. Otherwise the transmit messages of the parameterizable special module (PSM) control unit ("GPM_1H", "GPM_1I", "GPM_1J" and "GPM_1K") are not transmitted.
Structure of messages:
8 bit signals
2 byte signals
2 2-byte signals
Cycle times of sent messages:
2 x with 100 ms
1 x with 500 ms
1 x with 1000 ms
Other contents are listed in the "CAN matrix" in the document "PSM CAN matrix, function".
Coding for peripheral device CAN enable
The following parameters must be set when using the peripheral device CAN:
Peripheral device CAN active or inactive
"FMS standard" message package active or inactive
"ISO11992-2/3" message package active or inactive
Baud rate 125 kBit/s, 250 kBit/s or 500 kBit/s
Activation of free messages
Referenced documents
- gf5421s2004tra Signal lists, PSM, function
- gf5421s3038tra CAN matrix, PSM, function
- gf5421s5005tra Parameterizable special module (PSM) control unit component description
- gf5421s9998tra Overview of system components for parameterizable special module (PSM)