/// <summary>
/// Send an STX ETX formatted command (STX and ETX are added here).
/// Blocks until ack received or connection fails.
/// </summary>
/// <param name="data">the data to send (can be null)</param>
/// <param name="optionalRetries">Number of retries if no ACK is received</param>
/// <param name="optionalRetryTime">Amount of time (in ms) between retries</param>
/// <returns>True if an ACK was recieved, otherwise false</returns>
public bool SendCommand(byte[] data, int optionalRetries = SendContext.DEF_NUM_RETRIES, int optionalRetryTime = SendContext.DEF_RETRY_TIMEOUT_MS)
{
bool bFoundAck = false;
#region Add STX ETX, call new byte array "theData"
byte[] theData;
SendingContext.AddStxEtx(out theData, data);
#endregion
lock (SendingContext)
{
SendingContext.AckFound = new AutoResetEvent(false);
StxEtxAck = ACK_SEARCH;
try
{
while (optionalRetries >= 0)
{
string dat;
if (data != null)
{
dat = System.Text.Encoding.Default.GetString(data);
}
else
{
dat = "";
}
CommContext.LogMsg(TraceEventType.Verbose, "STXETX SENT: <STX>" + dat + "<ETX>");
CommContext.Write(theData);
bool reply = SendingContext.AckFound.WaitOne(optionalRetryTime);
if (reply == true) //got an ack!
{
bFoundAck = true;
break;
}
else
{
optionalRetries -= 1;
}
}
}
/* want the calling function to catch the exceptions... catch (Exception e)
* {
* Console.WriteLine(e);
* throw e;
* }*/
catch (Exception ex)
{
if (data != null)
{
CommContext.LogMsg(TraceEventType.Verbose, "Caught exception when waiting for an ACK to this message: <STX>" + System.Text.Encoding.Default.GetString(data.ToArray()) + "<ETX>. optionalRetries: " + optionalRetries.ToString() + ". Exception: " + ex.ToString());
}
else
{
CommContext.LogMsg(TraceEventType.Verbose, "Caught exception when waiting for an ACK to this message: <STX><ETX>. optionalRetries: " + optionalRetries.ToString() + ". Exception: " + ex.ToString());
}
}
finally
{
try { SendingContext.AckFound.Dispose(); }
catch { }
SendingContext.AckFound = null;
//important to prevent the STX/ETX handler from locking
if (StxEtxAck == ACK_SEARCH)
{
StxEtxAck = STX_SEARCH;
}
}
}
return(bFoundAck);
}
