diff --git a/encoder/encoder_datatype.h b/encoder/encoder_datatype.h
index 766175d7..7ed57e1d 100644
--- a/encoder/encoder_datatype.h
+++ b/encoder/encoder_datatype.h
@@ -155,9 +155,9 @@ typedef struct {
 	float s_offset;
 	float c_offset;
 	float filter_constant;
-	float phase_correction;
-	float sph;
-	float cph;
+	float phase_correction; //phase angle correction when encoder outputs sin(anle)/cos(angle+pase_correction)
+	float sph; // sin of the phase_correction angle
+	float cph; // cos of the phase_correction angle
 
 	ENCSINCOS_state state;
 } ENCSINCOS_config_t;