diff --git a/src_main/thread/pitimer.cpp b/src_main/thread/pitimer.cpp
index 0611649f..1ea4e183 100755
--- a/src_main/thread/pitimer.cpp
+++ b/src_main/thread/pitimer.cpp
@@ -61,6 +61,7 @@ _PITimerBase::_PITimerBase() {
 void _PITimerBase::setInterval(double i) {
 	interval_ = i;
 	if (isRunning()) {
+		piCout << "change interval runtime";
 		stop(true);
 		start();
 	}