Axel CANDPSX - DATA EXCHANGE between Profibus-DP and CAN; Introduction; Activating a Can Message; Setting the Type of Message

CANDPSX user manual rev 2 Page 23 of 42
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5 DATA EXCHANGE BETWEEN PROFIBUS-DP AND CAN
5.1 INTRODUCTION
Data exchange between Profibus and CAN is carried out by means of standard CAN messages
with 11-bit identifier. The maximum length of messages is 8 bytes. For each byte making up the
message it is possible to specify the corresponding source offset (if the message is outbound) or
destination offset (if the message is inbound) in the Profibus dual port.
The procedure to set up CAN messages and to map the data is the same for all the operating
modes. Up to 32 CAN messages are available which can be programmed for transmission or
reception, but each operating mode defines the maximum number of messages it can handle and
the methods to drive data transmission.
Data exchange between the Profibus dual port and CAN messages is performed synchronously
every time a data exchange request arrives from the Profibus-DP Master.
5.2 ACTIVATING A CAN MESSAGE
A CAN message is composed of the following elements:
• The type of message
• The ID
• 8 byte of user data
• The trigger object of the message (for outbound messages only)
5.2.1 Setting the type of message
To select the type of CAN message, set the parameters 2140h - 215Fh:
Property
Value
Parameters
2140h to 215Fh
Logic View menu
All parameters/Messages/Message n
Data type
8 bit unsigned int
Measurement unit
--
Value
0 = inactive message
1 = generic inbound message
2 = generic outbound message
5 = asynchronous inbound PDO of type 254
6 = asynchronous outbound PDO of type 254
Default value
0
Access
Read/Write
5.2.2 Setting the message ID
To set the message ID, set the parameters 2100h - 211Fh:
Property
Value
Parameters
2100h to 211Fh
Logic View menu
All parameters/Messages/Message n