Hi I have the problem, that I want to execute a 'ClockTick' each 100ms, and a 'Do_Process' when a Signal is received. If I use: char OSEvent; OSEvent = os_wait(K_SIG+K_IVL,100,0); switch (OSEvent) { case TMO_EVENT : { ClockTick(); break; } case SIG_EVENT : { Do_Process(); break; } default : { LogWrite("Unknown\n"); } } I have the problem, that 'ClockTick' is executed in shorter intervals than 100ms when a lot of Signals are received. Seems that the interval timer is reseted whenever a signal occurs. In this way 'ClockTick' can be executed more than 10 times in a second, but it must not! Well, I can also use a timer: OSEvent = os_wait(K_SIG+K_TMO,100,0); But in this way it is no guaranteed, that 'ClockTick' is executed every 100ms. If I receive a lot of Signals, then 'ClockTick' is never executed. How can I solve this problem. According to the manual this should work with an interval. Please help me Tom