diff --git a/src/gpsread.cpp b/src/gpsread.cpp
index 48f5a451..55d8ba2d 100644
--- a/src/gpsread.cpp
+++ b/src/gpsread.cpp
@@ -10,7 +10,7 @@ gpsStatus_t gps_status;
 TaskHandle_t GpsTask;
 
 #ifdef GPS_SERIAL
-HardwareSerial GPS_Serial(1);
+HardwareSerial GPS_Serial(1); // use UART #1
 #endif
 
 // initialize and configure GPS
diff --git a/src/if482.cpp b/src/if482.cpp
index e38f2216..d1fcf7cb 100644
--- a/src/if482.cpp
+++ b/src/if482.cpp
@@ -2,48 +2,65 @@
 
 /*
 
-IF482 Generator to control clocks with IF482 timeframe input (e.g. BÜRK BU190)
+IF482 Generator to control clocks with IF482 telegram input (e.g. BÜRK BU190)
    
-Example IF482 timeframe: "OAL160806F170400"
+Example IF482 telegram: "OAL160806F170400"
 
 IF482 Specification:
-https://www.buerk-mobatime.de/cfc/shop.cfc?method=deliverShopDoc&id=509
+http://www.mobatime.com/fileadmin/user_upload/downloads/TE-112023.pdf
 
-Standard Zeittelegramm (IF 482) mit lokaler Zeit
+The IF 482 telegram is a time telegram, which sends the time and date
+information as ASCII characters through the serial interface RS 232 or RS 422.
 
-Definition: Zeittelegramm (ASCII), endend auf die im Telegramm bezeichnete
-Sekunde: 9600 Bit/s, 7 Datenbits, gerade Parität, 1 Stoppbit. Jitter < 50ms.
+Communication parameters:
 
-Format:
-Byte    Bedeutung                              Zeichen     HEX Code
-1       Startzeichen                            O           4F
-2       Überwachung*                            A           41
-3       Lokale Zeit** (durch die Uhr angezeigt) L           4C
-4       Jahr Zehner                             0 .. 9      30 .. 39
-5       Jahr Einer                              0 .. 9      30 .. 39
-6       Monat Zehner                            0 oder 1    30 oder 31
-7       Monat Einer                             0 .. 9      30 .. 39
-8       Tag Zehner                              0 .. 3      30 .. 33
-9       Tag Einer                               0 .. 9      30 .. 39
-10      nicht verwendet                         F           46
-11      Stunden Zehner                          0 .. 2      30 .. 32
-12      Stunden Einer                           0 .. 9      30 .. 39
-13      Minuten Zehner                          0 .. 5      30 .. 35
-14      Minuten Einer                           0 .. 9      30 .. 39
-15      Sekunden Zehner                         0 .. 5      30 .. 35
-16      Sekunden Einer                          0 .. 9      30 .. 39
-17      Ende des Telegramms                     CR          0D
+Baud rate: 9600 Bit/s
+Data bits 7
+Parity: even
+Stop bit: 1
+Jitter: < 50ms
 
-*) Überwachung:
-'A': Korrekter Zeitempfang des Sendegerätes
-'M': Sendegerät hat mehr als 12 Stunden kein Zeitsignal empfangen
-Zeit wird bei 'A' und 'M' vom Uhrwerk übernommen.
+Interface : RS232 or RS422
 
-**) Lokale Zeit:
-'W': Winterzeit
-'S': Sommerzeit
-'L': Lokalzeit
-Wird überprüft, jedoch nicht vom Uhrwerk ausgewertet.
+Synchronization: Telegram ends at the beginning of the second
+specified in the telegram
+
+Cycle: 1 second
+
+Format of ASCII telegram string:
+
+Byte  Meaning             ASCII     Hex
+ 1    Start of telegram   O         4F
+ 2    Monitoring*         A         41
+ 3    Time-Season**       W/S/U/L   57 or 53
+ 4    Year tens           0 .. 9    30 .. 39
+ 5    Year unit           0 .. 9    30 .. 39
+ 6    Month tens          0 or 1    30 or 31
+ 7    Month unit          0 .. 9    30 .. 39
+ 8    Day tens            0 .. 3    30 .. 33
+ 9    Day unit            0 .. 9    30 .. 39
+10    Day of week***      1 .. 7    31 .. 37
+11    Hours tens          0 .. 2    30 .. 32
+12    Hours unit          0 .. 9    30 .. 39
+13    Minutes tens        0 .. 5    30 .. 35
+14    Minutes unit        0 .. 9    30 .. 39
+15    Seconds tens        0 .. 5    30 .. 35
+16    Seconds unit        0 .. 9    30 .. 39
+17    End of telegram     CR        0D
+
+*) Monitoring:
+With a correctly received time in the sender unit, the ASCII character 'A' is
+issued. If 'M' is issued, this indicates that the sender was unable to receive
+any time signal for over 12 hours (time is accepted with ‘A’ and ‘M’).
+
+**) Season:
+W: Standard time,
+S: Season time,
+U: UTC time (not supported by all systems),
+L: Local Time
+
+***) Day of week:
+not evaluated by model BU-190
 
 */
 
@@ -52,13 +69,13 @@ Wird überprüft, jedoch nicht vom Uhrwerk ausgewertet.
 // Local logging tag
 static const char TAG[] = "main";
 
-HardwareSerial IF482(IF482_PORT); // serial port 1
+HardwareSerial IF482(1); // use UART #1
 
 // initialize and configure GPS
 void if482_init(void) {
 
+  // open serial interface
   IF482.begin(HAS_IF482);
-  ESP_LOGI(TAG, "IF482 serial port opened");
 
   // use rtc 1Hz clock for triggering IF482 telegram send
   Rtc.SetSquareWavePinClockFrequency(DS3231SquareWaveClock_1Hz);
@@ -67,11 +84,13 @@ void if482_init(void) {
   // setup external interupt for active low RTC INT pin
   attachInterrupt(RTC_INT, IF482IRQ, FALLING);
 
+  ESP_LOGI(TAG, "IF482 generator initialized");
+
 } // if482_init
 
-char * if482Telegram(time_t t) {
+char *if482Telegram(time_t t) {
 
-  static char out[17] = {0}; // 16 bytes IF482 telegram plus null termination char
+  static char out[17] = {0}; // 16 bytes IF482 telegram + null termination char
   char buf[14] = {0};
 
   strcat_P(out, "O"); // <STX>
@@ -95,8 +114,8 @@ char * if482Telegram(time_t t) {
   strcat_P(out, "L"); // local time
 
   if (!timeNotSet) { // do we have valid time?
-    sprintf(buf, "%02u%02u%02uF%02u%02u%02u", year(t), month(t), day(t), hour(t),
-            minute(t), second(t));
+    sprintf(buf, "%02u%02u%02u%1u%02u%02u%02u", year(t), month(t), day(t),
+            weekday(t), hour(t), minute(t), second(t));
     strcat(out, buf);
   } else {
     strcat_P(out, "000000F000000");
@@ -108,8 +127,6 @@ char * if482Telegram(time_t t) {
 }
 
 // interrupt triggered routine
-void sendIF482(time_t t) {
-        IF482.write(if482Telegram(t));
-}
+void sendIF482(time_t t) { IF482.write(if482Telegram(t)); }
 
 #endif // HAS_IF482
\ No newline at end of file