diff --git a/scheduler/schedule.cpp b/scheduler/schedule.cpp
index b487848..ae149fd 100644
--- a/scheduler/schedule.cpp
+++ b/scheduler/schedule.cpp
@@ -295,6 +295,8 @@ int SensorScheduler::GetNextDuration(int short_addr, int &next_task_id) {
     long current_ts = GetLocalTs(); 
     nth_wave_start_slice_ = (current_ts_ - start_timestamp_) / wave_form_send_interval_;
     current_wave_start_ts_ = nth_wave_start_slice_ * wave_form_send_interval_ + start_timestamp_;
+    seconds_in_current_wave_slice_ = current_ts_ - current_wave_start_ts_;
+    nth_eigen_value_slice_ = seconds_in_current_wave_slice_ / eigen_value_send_interval_;
     long next_ts = CalcNextTimestamp(id, short_addr, next_task_id);
     int duration = next_ts - current_ts;
     if (duration < 0 || duration > eigen_value_send_interval_) {