/**
* Execute a transaction with a Jaguar that sets some property.
*
* <p>Jaguar always acks when it receives a message. If we don't wait for an ack, the message
* object in the Jaguar could get overwritten before it is handled.
*
* @param messageID The messageID to be used on the CAN bus (device number is added internally)
* @param data The up to 8 bytes of data to be sent with the message
* @param dataSize Specify how much of the data in "data" to send
*/
protected byte setTransaction(int messageID, byte[] data, byte dataSize)
throws CANTimeoutException {
int ackMessageID = JaguarCANProtocol.LM_API_ACK | m_deviceNumber;
// Make sure we don't have more than one transaction with the same Jaguar outstanding.
synchronized (m_transactionMutex) {
// Throw away any stale acks.
try {
receiveMessage(ackMessageID, kNoData, 0.0);
} catch (CANTimeoutException e) {
}
// Send the message with the data.
sendMessage(messageID | m_deviceNumber, data, dataSize);
// Wait for an ack.
dataSize = receiveMessage(ackMessageID, kNoData);
}
return dataSize;
}
