diff --git a/drv/b15f.cpp b/drv/b15f.cpp
index 67b041c..2ecff4e 100644
--- a/drv/b15f.cpp
+++ b/drv/b15f.cpp
@@ -140,6 +140,7 @@ std::vector<std::string> B15F::getBoardInfo(void)
 
 bool B15F::digitalWrite0(uint8_t port)
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_BA0);
 	usart.writeByte(port);
 	
@@ -149,6 +150,7 @@ bool B15F::digitalWrite0(uint8_t port)
 
 bool B15F::digitalWrite1(uint8_t port)
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_BA1);
 	usart.writeByte(port);
 	
@@ -158,18 +160,21 @@ bool B15F::digitalWrite1(uint8_t port)
 
 uint8_t B15F::digitalRead0()
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_BE0);
 	return usart.readByte();
 }
 
 uint8_t B15F::digitalRead1()
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_BE1);
 	return usart.readByte();
 }
 
 bool B15F::analogWrite0(uint16_t value)
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_AA0);
 	usart.writeInt(value);
 	
@@ -179,6 +184,7 @@ bool B15F::analogWrite0(uint16_t value)
 
 bool B15F::analogWrite1(uint16_t value)
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_AA1);
 	usart.writeInt(value);
 	
@@ -188,6 +194,7 @@ bool B15F::analogWrite1(uint16_t value)
 
 uint16_t B15F::analogRead(uint8_t channel)
 {
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_ADC);
 	usart.writeByte(channel);
 	return usart.readInt();
@@ -198,6 +205,7 @@ bool B15F::analogSequence(uint8_t channel_a, uint16_t* buffer_a, uint32_t offset
 	buffer_a += offset_a;
 	buffer_b += offset_b;
 	
+	usart.clearInputBuffer();
 	usart.writeByte(RQ_ADC_DAC_STROKE);
 	usart.writeByte(channel_a);
 	usart.writeByte(channel_b);
diff --git a/drv/b15f.h b/drv/b15f.h
index 4a12632..8b1b465 100644
--- a/drv/b15f.h
+++ b/drv/b15f.h
@@ -91,6 +91,8 @@ public:
 	
 	/*************************************/
 	
+	
+	
 	/*************************
 	 * Steuerbefehle für B15 *
 	 *************************/
diff --git a/drv/b15f.o b/drv/b15f.o
index d0b1584..bb61a6a 100644
Binary files a/drv/b15f.o and b/drv/b15f.o differ
diff --git a/drv/usart.cpp b/drv/usart.cpp
index d9c0dbf..2d4cf41 100644
--- a/drv/usart.cpp
+++ b/drv/usart.cpp
@@ -51,14 +51,15 @@ void USART::clearOutputBuffer()
 
 void USART::writeByte(uint8_t b)
 {
-	//std::cout << "write(): " << (int) b << std::endl;
-	if(write(file_desc, &b, 1) != 1)
+	int sent = write(file_desc, &b, 1);
+	if(sent != 1)
 		throw USARTException("Fehler beim Senden: writeByte()");
 }
 	
 void USART::writeInt(uint16_t d)
 {
-	if(write(file_desc, reinterpret_cast<char*>(&d), 2) != 2)
+	int sent = write(file_desc, reinterpret_cast<char*>(&d), 2);
+	if(sent != 2)
 		throw USARTException("Fehler beim Senden: writeInt()");
 }
 
@@ -102,28 +103,15 @@ uint8_t USART::readByte(void)
 	uint16_t elapsed = 0;
 	while(elapsed < timeout * 100)
 	{
-		int n_ready;
-		int code = ioctl(file_desc, FIONREAD, &n_ready);
-		if(code != 0)
-				std::cout << "n_ready code: " << code << std::endl;
-		
-		if(n_ready > 0)
-		{				
-			//std::cout << code << " \tready: " << n_ready << std::endl;
-			
-			code = read(file_desc, &b, 1);
-			if (code > 0)
-				return static_cast<uint8_t>(b);
-			if (code < 0)
-				std::cout << "usart code: " << code << std::endl;
-		}
-		
+		int code = read(file_desc, &b, 1);
+		if (code > 0)
+			return static_cast<uint8_t>(b);
+				
 		end = std::chrono::steady_clock::now();
 		elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
 	}
 	
-	if(elapsed >= timeout)
-		throw USARTException("Verbindung unterbrochen. (timeout)");
+	throw TimeoutException("Verbindung unterbrochen.", timeout);
 }
 
 uint16_t USART::readInt(void)
diff --git a/drv/usart.h b/drv/usart.h
index a52d74a..bc9c220 100644
--- a/drv/usart.h
+++ b/drv/usart.h
@@ -9,6 +9,7 @@
 #include <sys/ioctl.h>
 #include <termios.h>
 #include "usartexception.h"
+#include "timeoutexception.h"
 
 class USART
 {
diff --git a/drv/usart.o b/drv/usart.o
index 57ade56..209f02e 100644
Binary files a/drv/usart.o and b/drv/usart.o differ
diff --git a/gnuplotscript.gp b/gnuplotscript.gp
index d611d65..752e2b8 100644
--- a/gnuplotscript.gp
+++ b/gnuplotscript.gp
@@ -10,20 +10,20 @@ set y2range [0:50]
 set yrange [0:50]
 set label at 2,36 'U_{DS} [V] = 300' right
 set label at 2,33 'U_{DS} [V] = 325' right
-set label at 2,36 'U_{DS} [V] = 350' right
+set label at 2,21 'U_{DS} [V] = 350' right
 set label at 2,38 'U_{DS} [V] = 375' right
-set label at 2,5 'U_{DS} [V] = 400' right
+set label at 2,23 'U_{DS} [V] = 400' right
 set label at 2,23 'U_{DS} [V] = 425' right
 set label at 2,24 'U_{DS} [V] = 450' right
 set label at 2,24 'U_{DS} [V] = 475' right
-set label at 2,12 'U_{DS} [V] = 500' right
-set label at 2,13 'U_{DS} [V] = 525' right
-set label at 2,13 'U_{DS} [V] = 550' right
+set label at 2,25 'U_{DS} [V] = 500' right
+set label at 2,5 'U_{DS} [V] = 525' right
+set label at 2,6 'U_{DS} [V] = 550' right
 set label at 2,13 'U_{DS} [V] = 575' right
 set label at 2,13 'U_{DS} [V] = 600' right
-set label at 2,6 'U_{DS} [V] = 625' right
-set label at 2,6 'U_{DS} [V] = 650' right
-set label at 2,6 'U_{DS} [V] = 675' right
+set label at 2,13 'U_{DS} [V] = 625' right
+set label at 2,2 'U_{DS} [V] = 650' right
+set label at 2,2 'U_{DS} [V] = 675' right
 set label at 2,6 'U_{DS} [V] = 700' right
 set label at 2,2 'U_{DS} [V] = 725' right
 set label at 2,2 'U_{DS} [V] = 725' right
diff --git a/main b/main
index 6ab14c5..3b3b93b 100755
Binary files a/main and b/main differ
diff --git a/test_plot b/test_plot
index 9860ede..9dbebdd 100644
Binary files a/test_plot and b/test_plot differ