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159 Functions and outputs
HBM QuantumX
7.5 MX471
The MX471 module ensure a high − performance connection between a CANbus network and
the QuantumX system.
Four CAN interfaces are available, all working independently from each other.
The CANbus enables signals to be input to the measurement system and output as PDO
(Process Data Object).
CAN Output
The modular QuantumX data acquisition system can be individually assembled. FireWire
enables quantities measured using amplifiers or computed values to be transmitted to
specific modules in real time (isochronous signals).
For example: To send a measured temperature as a so
− called ”Process Data Object” (PDO)
over the CANbus via a specific node of the MX471, the temperature signal simply has to be
dragged onto the node using drag & drop. Parameterization is then performed automatically.
The CAN message needs to be completed in the corresponding dialog.
A parameterized MX471 node enables any signals or measured quantities to be cyclically
sent as CAN messages.
The CAN messages are sent to the CANbus at the data rate set for the source signal. With a
data rate > 4.800 Hz, the transmission rate is limited. A configurable divider enables the
transmission rate on the CANbus to be generally reduced.
It is essential to specify via software the baud rate and, if necessary, activation of a
termination resistor (bus termination) to ensure correct bus parameterization.
Parameterizing the CAN message requires:
S Definition of an identifier (decimal CAN − ID) and the corresponding format (11 or 29 bit)
S If necessary, divider to reduce the transmission rate.
Signals are sent using the 4 − Byte − Float format.
When parameterization of the node has been completed, a type *.dbc CAN database can be
generated. This database makes configuring a receiver node easier.
Additional protocols
The MX471 module supports the following protocols on up to 2 channels:
S CAN Calibration Protocol (CCP)
S eXtended Calibration Protocol (xCP-on-CAN)
These protocols are commonly used in the automotive industry to communicate with
parameter sets/signal lists from electronic control equipment.
The first step for parameterization of the individual MX471 channels requires the CANape
software tool from Vector Informatik. Based on an available control device description file
(*.a2l), CANape generates a signal description file (*.dbc) which is transferred to the channel
using the QuantumX − Assistant tool and parameterizes the respective CAN node. Seed&Key
encryption technology is supported.