Transport Request/Response
Contents
The Transport Request and Transport Response Transforms are used with transport protocol ISO15765 to send and receive data that is longer than a standard 8-byte CAN message. Transport Request breaks TP messages into standard CAN frames and Transport Response receives CAN frames and assembles the TP message. Set the desired CAN Arbitration IDs in Properties for proper execution. The Tester Present signal can be used to turn on and off sending of the Tester Present Keep Alive Message.
•Flow Control Addressing: Select the type of addressing to use for flow control messages. Select Match Request to use the same addressing as the original request message, or Always Physical to use physical addressing. •Flow Control Timeout (ms): How long the Transport Protocol waits for a Flow Control frame before timing out and canceling current transition. Default 1 sec. •Functional Tx Id: The CAN Arb ID for transport messages broadcast to all ECUs (for example, the Tester Present message). •Physical Tx Id: The physical CAN Arb ID for transport messages (messages sent to a specific ECU). •Tester Present Subfunction: The Subfunction ID to send with Tester Present messages. Typical values are $00 (normal response) or $80 (suppress positive response). Other values may be allowed. •Tester Present Transmission Interval (ms): Tester Present messages are transmitted at this rate. •Unique Id: If you have more than one pair of Transport Request/Response transforms, assign a unique number to both transforms to identify the pair. For example, assign an ID of 1 to both transforms connected to CAN A, and an ID of 2 to both transforms connected to CAN B. |
•Receive Id: Transport messages received from the ECU are reassembled using this CAN Arb ID. •Unique Id: If you have more than one pair of Transport Request/Response transforms, assign a unique number to both transforms to identify the pair. For example, assign an ID of 1 to both transforms connected to CAN A, and an ID of 2 to both transforms connected to CAN B. |
This diagram shows the Transport Transforms connected to a hardware CAN bus:
Click to expand.
You can have multiple concurrent diagnostic sessions on a bus as long as the Transmit and Receive IDs are different. Be sure to pair the Transforms using the Unique ID property.
If the ECU (SUT) sends a valid STmin in a flow control message, that value is used as the separation time between frames. If the ECU sends 0, we clamp it to between 1 and 127 milliseconds.
To override the flow control message, use the OverrideInterFrameDelay port. The value is an integer in milliseconds. Setting OverrideInterFrameDelay to 0 resets the Transform to use the value from the flow control message. Microsecond values are not supported.
If the Disable Flow Control port is set to zero (enabled), the Transport Response Transform generates automatic flow control messages with a separation time of zero. If the port is set to 1 (disabled), the Transform does not send flow control messages. You must manually generate the messages from a TestCase.
Use with Diagnostic Transforms
These Transforms are usually used in conjunction with the Diagnostic Request/Response Transforms.
Related Topics:
Diagnostic Request/Response Transforms
Sil/DiagSample Project