CANopen Field Bus
Operating Manual XCx 300 / 500 / 540 Version 09/08
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7.1.1
Process Data Objects (PDO)
The control unit can use byte, word and double word network
variables as mappable objects in PDOs.
The PLC program accesses network variables with the help of the
CANIO driver via a process data map.
Direct network variables, which can be accessed without a special
driver and without process map (!), are also provided.
We recommend using a CANopen configurator such as ProCANopen
to configure the communication relationships in the CANopen
network. All information on number, object index, data type, etc. can
be taken from the supplied EDS files.
As a device conforming to CiA DSP 302 (Framework for
Programmable CANopen Devices) / DSP 405 (Device Profile for IEC
1131 Programmable Devices), the XCx does not provide default
mapping for PDOs.
You can find a list of mappable objects in Parameterizing and
diagnosis data and Network variables.
7.1.2
Service Data Objects (SDO)
Specíal "SDO objects" are available for reading/writing up to 128
bytes of consistent user data.
If the PLC is to access these objects, corresponding arrays must first
be declared in the PLC code.
Object index
Direction
Address range
Number of
bytes
0x4100
Rx
Depending on
IO configuration
128
0x4110
Rx
128
0x4120
Rx
32
0x4130
Rx
64
0x4200
Tx
128
0x4210
Tx
128
0x4220
Tx
32
0x4230
Tx
64
Rx means externally writable by "Write Request"
Tx means externally readable by "Read Request"
7.1.3
Nodeguarding
Node guarding allows a guarding master to detect a failed slave. The
guarding process involves sending messages to the guarding ID
(100Eh) of the slave in periodic cycles. The slave replies with a
guarding message which may include a toggle bit.
If a Schleicher PLC is configured as the guarding master, a function
block can be used to evaluate guarding errors in the PLC program.