canMatch - Match received CAN message

Test if a particular CAN message has been received.

The PLT keeps only the single most recently received frame for each Arbitration ID on port. canMatch polls that retained frame — it does not search a history of previously received frames — so if several frames with the same msgId arrive, only the latest one is checked. Use canClear - Clear CAN Buffer beforehand to ensure a stale frame with the same ID doesn’t cause a false match.

If the b payload bytes are omitted, the command succeeds as soon as any frame with the matching msgId is received, regardless of payload. If b bytes are given, they are matched against the received frame’s payload as an exact-value prefix: the received payload must be at least as long as the number of b bytes supplied, and each supplied byte must equal the received byte at the same position. Trailing received bytes beyond the supplied b bytes are ignored — there is no partial-byte/wildcard mask. To check specific bytes without constraining the ones before them, supply all preceding bytes as well.

The command polls port until a matching frame arrives or the step times out. If no timeout: is set on the step, it defaults to 3 seconds.

Usage:

- command: canMatch <port> <msgId> [<b> <b> ...]
  [extractKey: <key>]
  [retry: <retryCount>]

Argument

Description

port

CAN port name: CAN0, CAN1, CAN2, etc.

msgId

CAN Message Arbitration ID (11-bit standard or 29-bit extended). Can be specified as a decimal, hex, or binary number, depending on prefix. Use 0x for hex and 0b for binary. If no prefix is specified, the value will be interpreted as decimal.

b

Payload bytes to match against a prefix of the received frame’s data, in order, starting at byte 0. Each byte can be specified as a decimal, hex, or binary number, depending on prefix. Use 0x for hex and 0b for binary. If no prefix is specified, the value will be interpreted as decimal. Omit all b bytes to match on msgId alone, irrespective of payload.

key

Key in which to store the matching CAN message’s payload, as a hex string (optional)

retryCount

Number of times to retry the test step (optional)

Note

The built-in CAN0 port does not support CAN-FD, so received frames on CAN0 are limited to 8-byte Classic CAN payloads. Frames longer than 8 bytes require an externally- attached USB CAN-FD dongle configured with FD via canCfg - Configure CAN interface.

Examples

See also