CANopen filter fields

Select CANopen and the Protocol layer. For source identifiers, RTR and the complete CAN frame payload, use the Physical layer and the CAN catalog.

Catalog

Field	Type	Meaning and applicability
protocol.type	String	Application protocol type: canopen
canopen.type	String	Message family, listed below
canopen.nodeId	Integer	Message node; for NMT, the target node, with 0 addressing all nodes
canopen.canId	Integer	Message CAN identifier
canopen.index	Integer	SDO/USDO object index when the message carries an object key
canopen.subIndex	Integer	SDO/USDO subindex when the key is present
canopen.request	Boolean	SDO/USDO request role, when determined
canopen.response	Boolean	SDO/USDO response role, when determined
canopen.abortCode	Integer	Abort code; only in SDO/USDO abort messages
canopen.nmtCommand	Integer	Command code; only in NMT messages
canopen.emcyCode	Integer	Emergency code; only in EMCY messages
canopen.data	Bytes	SDO/USDO transfer data, PDO payload, or message data for other types

A PDO message does not gain index and subIndex fields even when its values are decoded using a device description. These fields refer to SDO/USDO object keys. The current catalog has no filter for a decoded PDO signal name or physical value. See the filter language reference for comparisons with missing fields.

Message types

protocol.type == canopen selects the protocol; canopen.type distinguishes its message families. The canopen suggestion for protocol.type appears when the trace contains messages. The following canopen.type catalog is independent of the trace contents.

canopen.type	Messages
nmt	Network state management
sync	Synchronization
time	Time
bootup	Node startup
heartbeat	Node state reports
nodeGuard	Recognized Node Guarding traffic
emcy	Emergency message
sdo	SDO exchange
pdo	PDO process data
usdo	USDO exchange in CANopen FD

Unclassified messages use unknown. Distinguishing Heartbeat from Node Guarding depends on the observed frame; not every state response can be classified unambiguously without context.

USDO belongs to CANopen FD. See CAN FD settings for adapter and decoding requirements.

Examples

All recognized messages for node 5:

canopen.nodeId == 5

Broadcast NMT targets node 0 and is excluded above. Include it with:

canopen.nodeId == 5 or (canopen.type == nmt and canopen.nodeId == 0)

Access to object 0x1018:1:

canopen.nodeId == 5 and canopen.type == sdo and canopen.index == 0x1018 and canopen.subIndex == 1

Segments without an object key lack these fields. Use a broader filter for the entire transfer:

canopen.nodeId == 5 and canopen.type == sdo

SDO/USDO aborts:

exists(canopen.abortCode)

Node emergencies:

canopen.nodeId == 5 and canopen.type == emcy

PDO with a particular CAN ID:

canopen.type == pdo and canopen.canId == 0x185

NMT command 0x01 for node 5 or the whole network:

canopen.type == nmt and canopen.nmtCommand == 0x01 and canopen.nodeId in (0, 5)

NMT has no SDO/USDO request role. Do not add canopen.request == true to find NMT commands.

See node state, object access and PDO data for further guidance.