Object Dictionary - Siemens Simatic Operating Instructions Manual

Functions
4.1 CANopen
4.1.1.2

Object dictionary

Structure of the object dictionary (OD)
All communication objects and all user objects are organized in the object dictionary (OD).
The areas used by the PN/CAN LINK are:
OD entry
0x1000 ... 0x1FFF
0x2000 ... 0x2FFF
Default settings and initialization
The default values specified for process data in the TIA Portal are used only for initialization
of the values in the OD. The OD entries are created by the S7 controller during configuration
of the PN/CAN LINK and preallocated with the configured values.
In "CANopen Manager" mode, the PN/CAN LINK remembers for all OD entries whose
content was sent as cyclic PROFINET data to the S7 controller whether a PDO with the data
has already been received since the last reset to the default values. In "CANopen Slave"
mode, the PN/CAN LINK monitors whether the entries were written at least once per SDO or
if a matching PDO was received. This information is compressed into one bit and sent
cyclically as group status of all data in the PROFINET data to the S7 controller.
According to the CiA standard "CiA 301", the default values are always applied to the OD in
the NMT state "Initialization", substate "Reset Application".
This state is passed through in the following cases:
● After configuration/reconfiguration of the PN/CAN LINK by the S7 controller
● After reset of the PN/CAN LINK by the reset bit from the S7 controller
● After receipt of the NMT command "Reset Node" (only in "CANopen Slave" mode)
● After reset of the PN/CAN LINK and all nodes due to a heartbeat error
(only in "CANopen Manager" mode and only when the error response is configured
accordingly, see Monitoring functions (Page 34))
The following actions are being executed in the process:
● The default value is written to the OD.
● The information whether the OD entry has been written by the CANopen side once before
is reset.
20
Meaning
Communication profile
Process data from/to PROFINET
SIMATIC PN/CAN LINK
Operating Instructions, 03/2018, A5E39895388-AB