diff --git a/df_datalink_sp/src/system_monitor.h b/df_datalink_sp/src/system_monitor.h
index 483a075..e60fbf8 100644
--- a/df_datalink_sp/src/system_monitor.h
+++ b/df_datalink_sp/src/system_monitor.h
@@ -61,9 +61,9 @@ typedef struct
 typedef struct
 {
 	uint32_t dataId_lj;
-	uint8_t data_lj[PAYLOAD_LJ];
+	uint8_t data_lj[PAYLOAD_LEN];
 	uint32_t dataId_flj;
-	uint8_t data_flj[PAYLOAD_FLJ];
+	uint8_t data_flj[PAYLOAD_LEN];
 } PAYLOAD;
 
 typedef struct
@@ -73,7 +73,7 @@ typedef struct
 	uint8_t slotNo;
 	uint8_t frameType;
 	// Payload
-	uint8_t payload[256];
+	uint8_t payload[PAYLOAD_LEN];
 	// Time sync info
 	uint64_t tmStamp;
 	uint32_t tmDevi;