diff --git a/api/apibasic/cmdid.hpp b/api/apibasic/cmdid.hpp
index 5712da2..b024f5c 100644
--- a/api/apibasic/cmdid.hpp
+++ b/api/apibasic/cmdid.hpp
@@ -1,10 +1,6 @@
 #pragma once
 #include <stdint.h>
 
-#define CMDID(cmdid, cmdSubId) ((cmdid << 8) + cmdSubId)
-
-#define NEW_CMDID(cmdid, cmdSubId) ((cmdid * 100) + cmdSubId)
-
 namespace iflytop {
 namespace zcr {
 typedef enum {
diff --git a/api/apibasic/packet_interface.hpp b/api/apibasic/packet_interface.hpp
index e6cfcb5..7d04227 100644
--- a/api/apibasic/packet_interface.hpp
+++ b/api/apibasic/packet_interface.hpp
@@ -5,12 +5,13 @@ namespace iflytop {
 namespace zcr {
 #pragma pack(push, 1)
 typedef struct {
-  uint16_t packetindex;
-  uint16_t cmdMainId;   // cmd main id
-  uint8_t  cmdSubId;    // cmd sub id
-  uint8_t  packetType;  //
-  uint16_t moduleid;    // module id
-  uint8_t  data[];
+  int8_t  packetType;
+  int16_t cmdid;
+  int8_t  moduleId;
+  int8_t  index;
+  int8_t  datalen;
+  uint8_t data[];
+  /* int8_t  checksum;*/
 } zcr_cmd_header_t;
 #pragma pack(pop)
 
@@ -21,11 +22,8 @@ typedef enum {
   kptv2_event     = 3,
 } zcan_cmd_packet_type_t;
 
+
 }  // namespace zcr
 }  // namespace iflytop
 
-#define CMD_SUB_ID(cmdid)   (cmdid & 0xff)
-#define MODULE_CMDID(cmdid) (cmdid >> 8)
 
-#define STEP_MOTOR_ID_OFF 100
-#define XY_MOTOR_ID_OFF   200
diff --git a/api/apibasic/protocol_constant.hpp b/api/apibasic/protocol_constant.hpp
index faa241f..0cac6ca 100644
--- a/api/apibasic/protocol_constant.hpp
+++ b/api/apibasic/protocol_constant.hpp
@@ -1 +1 @@
-#define ZCANCMD_READ_BUF_MAX_SIZE 512
\ No newline at end of file
+#define ZCANCMD_READ_BUF_MAX_SIZE 64
\ No newline at end of file