CAN
CX8050, CX8051 - Embedded-PCs for
CANopen and CAN
77
Version: 1.4
The default PDOs for drives contain 2 bytes each of a control and status word and a set or actual value for
the relevant axis.
The current mapping can be read by means of corresponding entries in the object directory. These are
known as the mapping tables. The first location in the mapping table (sub-index 0) contains the number of
mapped objects that are listed after it. The tables are located in the object directory at index 0x1600ff for the
RxPDOs and at 0x1A00ff for the TxPDOs.
Digital and analog input/output modules: Read out the I/O number
The current number of digital and analog inputs and outputs can be determined or verified by reading out the
corresponding application objects in the object directory:
Parameters
Object directory address
Number of digital input bytes Index 0x6000, sub-index 0
Number of digital output bytes Index 0x6200, sub-index 0
Number of analog inputs Index 0x6401, sub-index 0
Number of analog outputs Index 0x6411, sub-index 0
Variable mapping
As a rule, the default mapping of the process data objects already satisfies the requirements. For special
types of application the mapping can nevertheless be altered: the Beckhoff CANopen Bus Couplers, for
instance, thus support variable mapping, in which the application objects (input and output data) can be
freely allocated to the PDOs. The mapping tables must be configured for this: as from Version 4 of
CANopen, only the following procedure is permitted, and must be followed precisely:
1. First delete the PDO (set 0x1400ff, or 0x1800ff, sub-index 1, bit 31 to "1")
2. Set sub-index 0 in the mapping parameters (0x1600ff or 0x1A00ff) to "0"
3. Change mapping entries (0x1600ff or 0x1A00ff, SI 1..8)
4. Set sub-index 0 in the mapping parameters to the valid value. The device then checks the entries for
consistency.
5. Create PDO by entering the identifier (0x1400ff or 0x1800ff, sub-index 1).
Summary of Contents for CX8050
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