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85201A_RK5C_User Manual_02-2017_ENG
GEFRAN spa
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10. ERROR CONTROL SERVICES
The error control services are used to detect failures within a CAN-based network. The RK5 CANopen device makes
use of the heartbeat mechanism.
The heartbeat mechanism is established by cyclically transmitting the heartbeat message. If the heartbeat cycle fails for
the heartbeat producer the local application on the heartbeat consumer, aware of this heartbeat message, will be informed
about that event.
The format of the heartbeat message is explained in the following figure.
COB-ID Rx/Tx
DLC
Data
D0
D1
D2
D3
D4
D5
D6
D7
700h +
Node-ID
Tx
1
NMT
state
-
-
-
-
-
-
-
Figure 49 - Heartbeat message format
The first byte of the heartbeat message data field contains the actual CANopen Network Management State of the
CANopen device, as shown in the following table.
Bit field
Value
Description
NMT state
0
Reserved (see boot-up protocol)
4
Stopped
5
Operational
127
Pre-operational
Table 13 - NMT state field in heartbeat message
For the RK5 CANopen device the heartbeat is disabled by default. It can be programmed through object 1017h.