Hello! I've an Timer-Interrupt Routine (timer 3 with reload) with will served every 10 ms! In this Interrupt-Routine, I send 2 Messages via the CAN Interface. Now, I send the second message straight after the first, and the problem is, that the second message won't send in a 10 ms rhytm but often longer (up to 400 ms!). Now I use a global variable, where I decide which message to send; when the value is 0, send the first message, und change the value to 1, then send message 2 and set the value to 0 and so on! I declared an int (I also tried unsigned int, char ...). I have set the value of the variable to 0 in the "main" function, but in the Interrupt Service-Routine, the value ist "FF", and when I try to change to value inside the Interrupt-Service Routine, it has no effect! Is there any other way to transfer data between th "main" and the Interrupt Routine? THX in advance! Have a nice day! SVEN