/// <summary>
/// Task for processing received data running in thread
/// </summary>
private void ModbusRtuLinkTask()
{
while (true)
{
Thread.Sleep(0);
int value;
switch (ActualState)
{
case ModbusRtuLinkState.INIT:
// Init mode, wait for first 3.5 char framing timeout
break;
case ModbusRtuLinkState.IDLE:
// Idle mode, wait for incoming message
value = PHY.Receive();
if (value != -1)
{
byte ReceivedByte = Convert.ToByte(value);
ActualFrameIndex = 0;
ActualFrame[ActualFrameIndex++] = ReceivedByte;
ActualState = ModbusRtuLinkState.RECEIVING;
FramingTimer.Start();
}
break;
case ModbusRtuLinkState.RECEIVING:
// Receive all message bytes until framing timeout
value = PHY.Receive();
if (value != -1)
{
FramingTimer.Stop();
byte ReceivedByte = Convert.ToByte(value);
ActualFrame[ActualFrameIndex++] = ReceivedByte;
FramingTimer.Start();
}
break;
case ModbusRtuLinkState.PROCESSING:
// Process message
ProcessReceivedData();
ActualState = ModbusRtuLinkState.IDLE;
break;
}
}
}
/// <summary>
/// Task for processing received data running in thread
/// </summary>
private void ModbusAsciiLinkTask()
{
int threadDelay = 10;
while (true)
{
Thread.Sleep(threadDelay);
// Pop byte from receive ring buffer
int value = PHY.Receive();
if (value != -1)
{
byte ReceivedByte = Convert.ToByte(value);
switch (ActualState)
{
// Link is idle, wait for start character
case ModbusAsciiLinkState.IDLE:
if (ReceivedByte == ':')
{
// Start character received, start timeout timer and set state to receiving
TkickMessageId = ActualMessageId;
TimeoutCounter.Start();
// Reset reception buffer index
ActualFrameIndex = 0;
threadDelay = 0;
ActualState = ModbusAsciiLinkState.RECEIVING;
}
break;
case ModbusAsciiLinkState.RECEIVING:
// Link is receiving a message
if (ReceivedByte == '\n')
{
// Stop character received, stop timeout timer
TimeoutCounter.Stop();
// Check data integrity and notify upper layer
ProcessReceivedData();
// Set state to idle
ActualState = ModbusAsciiLinkState.IDLE;
threadDelay = 10;
// Increment message id
ActualMessageId++;
break;
}
if (ReceivedByte == '\r')
{
// do not store CR character
break;
}
if (ActualFrameIndex < ActualFrame.Length)
{
// Write received byte buffer
ActualFrame[ActualFrameIndex++] = ReceivedByte;
}
// If buffer overflow occured, skip and wait for timeout
break;
default:
break;
}
}
}
}