diff --git a/firmware/command_ctrl.ino b/firmware/command_ctrl.ino
index 12a348e..fdea09d 100644
--- a/firmware/command_ctrl.ino
+++ b/firmware/command_ctrl.ino
@@ -255,14 +255,9 @@ void cc_startMeasurement()
     //    MSG_TYPE_MEAS_FREQ_INFO
     sendSOM();
     Serial.write(MSG_TYPE_MEAS_FREQ_INFO);
-    Serial.write((uint8_t)((freq & 0xff000000) >> 24));
-    Serial.write((uint8_t)((freq & 0x00ff0000) >> 16));
-    Serial.write((uint8_t)((freq & 0x0000ff00) >>  8));
-    Serial.write((uint8_t) (freq & 0x000000ff));
-    Serial.write((uint8_t)((a0_sum & 0xff00) >> 8));
-    Serial.write((uint8_t) (a0_sum & 0x00ff));
-    Serial.write((uint8_t)((a1_sum & 0xff00) >> 8));
-    Serial.write((uint8_t) (a1_sum & 0x00ff));
+    send32BitValue(freq);
+    send16BitValue(a0_sum);
+    send16BitValue(a1_sum);
     sendEOM();
 
     si5351.output_enable(SI5351_CLK0, 0); // disable clock output 0
@@ -285,20 +280,10 @@ void cc_getConfig()
 {
   sendSOM();
   Serial.write(MSG_TYPE_CONFIG);
-  Serial.write((uint8_t)((start_freq & 0xff000000) >> 24));
-  Serial.write((uint8_t)((start_freq & 0x00ff0000) >> 16));
-  Serial.write((uint8_t)((start_freq & 0x0000ff00) >>  8));
-  Serial.write((uint8_t) (start_freq & 0x000000ff));
-  Serial.write((uint8_t)((end_freq & 0xff000000) >> 24));
-  Serial.write((uint8_t)((end_freq & 0x00ff0000) >> 16));
-  Serial.write((uint8_t)((end_freq & 0x0000ff00) >>  8));
-  Serial.write((uint8_t) (end_freq & 0x000000ff));
-  Serial.write((uint8_t)((step_freq & 0xff000000) >> 24));
-  Serial.write((uint8_t)((step_freq & 0x00ff0000) >> 16));
-  Serial.write((uint8_t)((step_freq & 0x0000ff00) >>  8));
-  Serial.write((uint8_t) (step_freq & 0x000000ff));
-  Serial.write((uint8_t)((intervall & 0xff00) >> 8));
-  Serial.write((uint8_t) (intervall & 0x00ff));
+  send32BitValue(start_freq);
+  send32BitValue(end_freq);
+  send32BitValue(step_freq);
+  send16BitValue(intervall);
   Serial.write((uint8_t) drive_str);
   sendEOM();
 }
@@ -372,10 +357,7 @@ void cc_saveDefaults(void)
 
 void cc_setClkCorrection(void)
 {
-  uint32_t tmp_corr  = (uint32_t)cc_read_data[0] << 24;
-           tmp_corr += (uint32_t)cc_read_data[1] << 16;
-           tmp_corr += (uint32_t)cc_read_data[2] <<  8;
-           tmp_corr += (uint32_t)cc_read_data[3];
+  uint32_t tmp_corr = read32BitDataFromBuffer(0);
 
   si5351.set_correction(tmp_corr);
 
@@ -389,10 +371,7 @@ void cc_getClkCorrection(void)
   uint32_t tmp_corr = si5351.get_correction();
 
   sendSOM();
-  Serial.write((uint8_t)((tmp_corr & 0xff000000) >> 24));
-  Serial.write((uint8_t)((tmp_corr & 0x00ff0000) >> 16));
-  Serial.write((uint8_t)((tmp_corr & 0x0000ff00) >>  8));
-  Serial.write((uint8_t) (tmp_corr & 0x000000ff));
+  send32BitValue(tmp_corr);
   sendEOM();
 }
 
@@ -411,11 +390,9 @@ void cc_init()
 void cc_abort()
 {
   // send abort message, then init
-  char* tmp = "     ";
-  sprintf(tmp, "%c%c%c%c%c", MSG_SOM1, MSG_SOM2,
-                             MSG_TYPE_ANSWER_NOK,
-                             MSG_EOM1, MSG_EOM2);
-  Serial.write(tmp);
+  sendSOM();
+  Serial.write(MSG_TYPE_ANSWER_NOK);
+  sendEOM();
 
   cc_init();
 }
@@ -535,3 +512,19 @@ void sendEOM()
 
 /*****************************************************************************/
 
+void send32BitValue(uint32_t value)
+{
+  Serial.write((uint8_t)((value & 0xff000000) >> 24));
+  Serial.write((uint8_t)((value & 0x00ff0000) >> 16));
+  Serial.write((uint8_t)((value & 0x0000ff00) >>  8));
+  Serial.write((uint8_t) (value & 0x000000ff));
+}
+
+void send16BitValue(uint16_t value)
+{
+  Serial.write((uint8_t)((value & 0xff00) >> 8));
+  Serial.write((uint8_t) (value & 0x00ff));
+}
+
+/*****************************************************************************/
+