diff --git a/Modbus_communication/Modbus_RTU_Salve/RTU_Salve.h b/Modbus_communication/Modbus_RTU_Salve/RTU_Salve.h
index b2f0d44..c3314e0 100644
--- a/Modbus_communication/Modbus_RTU_Salve/RTU_Salve.h
+++ b/Modbus_communication/Modbus_RTU_Salve/RTU_Salve.h
@@ -4,5 +4,6 @@
 #include "common.h"
 #define Device_ID 0x09
 #define MAX_Address 9999
+#define MAX_NUMBER 256
 
 #endif
\ No newline at end of file
diff --git a/Modbus_communication/Modbus_RTU_Salve/common.h b/Modbus_communication/Modbus_RTU_Salve/common.h
index 3443844..b68fe29 100644
--- a/Modbus_communication/Modbus_RTU_Salve/common.h
+++ b/Modbus_communication/Modbus_RTU_Salve/common.h
@@ -6,8 +6,14 @@
 #include <iostream>
 using namespace std;
 
-#define MAX_NUMBER 300
-
 unsigned int Count_Read_date_number(int Function_code, unsigned int Operations_Number);
+HANDLE Init_COM(LPCTSTR Port, int baud_rate, BYTE date_bits, BYTE stop_bit, BYTE parity);
+bool SendData(HANDLE m_hComm, char* data, int len);
+string Input_COMM(void);
+unsigned int Input_Baud_Rate(void);
+BYTE Input_Date_Bits(void);
+BYTE Input_Stop_Bits(BYTE Date_Bits);
+BYTE Input_Parity(void);
+UINT16 CRC_16(UINT8 *Data, unsigned int CRC_Len);
 
 #endif
\ No newline at end of file