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PME-MP55
HBM A0563-5.6 en
7 CAN interface description
7.1 Introduction
The MP55 module has a built-in CAN-interface which may be used not only
for data transmission but also for assigning parameters to the module. The
baud rate is selectable; the maximum possible is 1 MBaud. The interface pro-
tocol is based on the CANopen standard.
7.2 Cyclical data transmission
Cyclical data is transmitted in the form of “Process Data Objects” (PDOs, as
defined in CANopen). The measurement module sends the measured values
concerned cyclically without additional flags, under a previously defined CAN
identifier. No prompt message is needed. A parameter defines how often the
PDOs are sent (see object directory). Data formats with a length of more than
one byte are always sent in the sequence LSB-MSB.
Send PDO:
CAN identifier 384 (180 Hex) + module address
1st-4th data byte Value (LSB-MSB), integer 32
5th data bytes Status (object 2010)
Receive PDO:
CAN identifier 512 (200 Hex) + module address
1st data byte Control word (object 2630)
In addition to these predefined PDOs, it is possible to set up more PDOs as
defined in CANopen (CiA-DS 301) using a technique known as mapping. Ap-
propriate tools for this purpose are commercially available.
The exchange of cyclical PDOs only starts after the module has been placed
in ”Operational” status. This happens when the message ”Start_Re-
mote_Node” is sent
CAN identifier 0
1st data byte 1
2nd data byte Module address (0 = all)
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