--- title: "STM32 drives w5500 to port FreeModbus to implement ModbusTCP" url: "https://maker.wiznet.io/praveen_k/projects/STM32-drives-w5500-to-port-FreeModbus-to-implement-ModbusTCP/" markdown_url: "https://maker.wiznet.io/praveen_k/projects/STM32-drives-w5500-to-port-FreeModbus-to-implement-ModbusTCP/md" type: "UCC: User Created Content" author: "praveen_k" original_author: "praveen_k" original_url: "https://cxymm.net/article/qq_15181569/105042842" published: "2022-02-08" language: "en" hardware: ["WIZnet W5500", "STM32"] likes: 0 views: 427 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # STM32 drives w5500 to port FreeModbus to implement ModbusTCP > STM32 drives w5500 to port FreeModbus to implement ModbusTCP Original author: praveen_k (source: https://cxymm.net/article/qq_15181569/105042842) ## Components - **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500)) - **STM32** x 1 WIZnet parts: W5500 ([Datasheet](https://docs.wiznet.io/Product/Chip/Ethernet/W5500/datasheet?utm_source=maker&utm_medium=project&utm_campaign=w5500), [product hub](https://maker.wiznet.io/products/w5500/)) ## Documents and links - [STM32 driver w5500 transplanting FreeModbus to realize ModbusTCP complete code download](https://download.csdn.net/download/qq_15181569/12264015) (code) ## Article First, we download the FreeModbus source code, then put it in our own project, create a new MODBUS_TCP and PORT_TCP folder, and then copy the relevant files into it, as shown in the following figure: ![insert image description here](https://img-blog.csdnimg.cn/20200323102539294.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE1MTgxNTY5,size_16,color_FFFFFF,t_70#pic_center)Then modify the code in porttcp: first define an array to receive data : ```java static UCHAR aucTCPBuf[MB_TCP_BUF_SIZE]; //接收??? ``` Then initialize the socket connection in xMBTCPPortInit, and then listen to the port. ```java BOOL xMBTCPPortInit( USHORT usTCPPort ) { BOOL bOkay = FALSE; // ??端口 Modbus-TCP 端口 socket_init(SOCK_TCP_PORT,Sn_MR_TCP_TCP,local_tcp_port++,Sn_MR_ND_TCP); listen_tcp_socket(SOCK_TCP_PORT); bOkay = TRUE; return bOkay; } ``` Then send the data in the xMBTCPPortSendResponse function ```java BOOL xMBTCPPortSendResponse(const UCHAR * pucMBTCPFrame, USHORT usTCPLength ) { send_tcp_socket_data(SOCK_TCP_PORT,(UCHAR*)pucMBTCPFrame,usTCPLength); return TRUE; } ``` Then perform receive and other operations at xMBPortTCPPool ```java BOOL xMBPortTCPPool( void ) { unsigned short int us_rlen; unsigned char i; i=get_tcp_socket_state(SOCK_TCP_PORT); if(i==SOCK_ESTABLISHED_TCP) { if(get_tcp_socket_irq(SOCK_TCP_PORT) & Sn_IR_CON_TCP) //?看中?有?有?生 { clear_tcp_socket_irq(SOCK_TCP_PORT, Sn_IR_CON_TCP); /*?除接收中??志位*/ } us_rlen=get_tcp_rx_buffer_size(SOCK_TCP_PORT); //?取接收到的?据字? /*定?len?已接收?据的?度*/ if(us_rlen==0) //?有接收到?据 return FALSE; //返回 else { recv_tcp_socket_data(SOCK_TCP_PORT,aucTCPBuf,us_rlen); //接收?据 /*接收?自Server的?据*/ printf("receivern"); usTCPBufLen=us_rlen; } ( void )xMBPortEventPost( EV_FRAME_RECEIVED ); //?送已接收到新?据到Modbus-TCP??机 } else if(i==SOCK_CLOSED_TCP) //如果socket?? { socket_init(SOCK_TCP_PORT,Sn_MR_TCP_TCP,local_tcp_port++,Sn_MR_ND_TCP);//重新初始化 } else if(i==SOCK_INIT_TCP) //如果socket初始化完?，??端口 { listen_tcp_socket(SOCK_TCP_PORT); } else if(i==SOCK_CLOSE_WAIT_TCP) //如果socket等待??，??socket?接 { close_tcp_socket(SOCK_TCP_PORT); } return TRUE; } ``` Secondly, the functions of reading coil, writing coil, reading discrete input, writing holding register, reading holding register, and reading input register should be realized, as follows: ```c #define REG_INPUT_START 0x0001 //?入寄存器起始地址 #define REG_INPUT_NREGS 8 //?入寄存器?量 #define REG_HOLDING_START 0x0001 //保持寄存器起始地址 #define REG_HOLDING_NREGS 8 //保持寄存器?量 #define REG_COILS_START 0x0001 //?圈起始地址 #define REG_COILS_SIZE 16 //?圈?量 #define REG_DISCRETE_START 0x0001 //??寄存器其?地址 #define REG_DISCRETE_SIZE 16 //??寄存器?量 //?入寄存器?容 uint16_t usRegInputBuf[REG_INPUT_NREGS] = { 0x1000,0x1001,0x1002,0x1003,0x1004,0x1005,0x1006,0x1007}; //保持寄存器?容 uint16_t usRegHoldingBuf[REG_HOLDING_NREGS] = { 0x2000,0x2001,0x2002,0x2003,0x2004,0x2005,0x2006,0x2007}; //?圈?? uint8_t ucRegCoilsBuf[REG_COILS_SIZE] = { 0x01,0x01,0x00,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00}; //?散寄存器?容 uint8_t ucRegDiscreteBuf[REG_DISCRETE_SIZE] = { 0x01,0x01,0x00,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x01}; /**************************************************************************** * 名 ?：eMBRegInputCB * 功 能：?取?入寄存器，??功能?是 04 eMBFuncReadInputRegister * 入口??：pucRegBuffer: ?据?存?，用于??主机 * usAddress: 寄存器地址 * usNRegs: 要?取的寄存器?? * 出口??： * 注 意：上位机??的 ?格式是: SlaveAddr(1 Byte)+FuncCode(1 Byte) * +StartAddrHiByte(1 Byte)+StartAddrLoByte(1 Byte) * +LenAddrHiByte(1 Byte)+LenAddrLoByte(1 Byte)+ * +CRCAddrHiByte(1 Byte)+CRCAddrLoByte(1 Byte) * 3 ? ****************************************************************************/ eMBErrorCode eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs ) { eMBErrorCode eStatus = MB_ENOERR; int iRegIndex; if( ( usAddress >= REG_INPUT_START ) && ( usAddress + usNRegs <= REG_INPUT_START + REG_INPUT_NREGS ) ) { iRegIndex = ( int )( usAddress - REG_INPUT_START ); while( usNRegs > 0 ) { *pucRegBuffer++ = ( UCHAR )( usRegInputBuf[iRegIndex] >> 8 ); *pucRegBuffer++ = ( UCHAR )( usRegInputBuf[iRegIndex] & 0xFF ); iRegIndex++; usNRegs--; } } else { eStatus = MB_ENOREG; } return eStatus; } /**************************************************************************** * 名 ?：eMBRegHoldingCB * 功 能：??功能?有：06 ?保持寄存器 eMBFuncWriteHoldingRegister * 16 ?多?保持寄存器 eMBFuncWriteMultipleHoldingRegister * 03 ?保持寄存器 eMBFuncReadHoldingRegister * 23 ??多?保持寄存器 eMBFuncReadWriteMultipleHoldingRegister * 入口??：pucRegBuffer: ?据?存?，用于??主机 * usAddress: 寄存器地址 * usNRegs: 要??的寄存器?? * eMode: 功能? * 出口??： * 注 意：4 ? ****************************************************************************/ eMBErrorCode eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs, eMBRegisterMode eMode ) { eMBErrorCode eStatus = MB_ENOERR; int iRegIndex; if((usAddress >= REG_HOLDING_START)&& ((usAddress+usNRegs) <= (REG_HOLDING_START + REG_HOLDING_NREGS))) { iRegIndex = (int)(usAddress - REG_HOLDING_START); switch(eMode) { case MB_REG_READ://? MB_REG_READ = 0 while(usNRegs > 0) { *pucRegBuffer++ = (u8)(usRegHoldingBuf[iRegIndex] >> 8); *pucRegBuffer++ = (u8)(usRegHoldingBuf[iRegIndex] & 0xFF); iRegIndex++; usNRegs--; } break; case MB_REG_WRITE://? MB_REG_WRITE = 0 while(usNRegs > 0) { usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8; usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++; iRegIndex++; usNRegs--; } break; } } else//?? { eStatus = MB_ENOREG; } return eStatus; } /**************************************************************************** * 名 ?：eMBRegCoilsCB * 功 能：??功能?有：01 ??圈 eMBFuncReadCoils * 05 ??圈 eMBFuncWriteCoil * 15 ?多??圈 eMBFuncWriteMultipleCoils * 入口??：pucRegBuffer: ?据?存?，用于??主机 * usAddress: ?圈地址 * usNCoils: 要??的?圈?? * eMode: 功能? * 出口??： * 注 意：如??器 * 0 ? ****************************************************************************/ eMBErrorCode eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils, eMBRegisterMode eMode ) { eMBErrorCode eStatus = MB_ENOERR; int iRegIndex; u8 i; USHORT readNumber=usNCoils; USHORT coilValue=0x0000; if((usAddress >= REG_COILS_START)&& ((usAddress+usNCoils) <= (REG_COILS_START + REG_COILS_SIZE))) { iRegIndex = (int)(usAddress + usNCoils-REG_COILS_START); switch(eMode) { case MB_REG_READ://? MB_REG_READ = 0 for(i=0;i>8)&0x00ff; } break; case MB_REG_WRITE://? MB_REG_WRITE = 1 while(usNCoils > 0) { // usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8; // usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++; iRegIndex++; usNCoils--; } break; } } else//?? { eStatus = MB_ENOREG; } return eStatus; } /**************************************************************************** * 名 ?：eMBRegDiscreteCB * 功 能：?取?散寄存器，??功能?有：02 ??散寄存器 eMBFuncReadDiscreteInputs * 入口??：pucRegBuffer: ?据?存?，用于??主机 * usAddress: 寄存器地址 * usNDiscrete: 要?取的寄存器?? * 出口??： * 注 意：1 ? ****************************************************************************/ eMBErrorCode eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete ) { eMBErrorCode eStatus = MB_ENOERR; int iRegIndex; u8 i; USHORT readNumber=usNDiscrete; USHORT coilValue=0x0000; iRegIndex = (int)(usAddress + usNDiscrete-REG_DISCRETE_START); if((usAddress >= REG_DISCRETE_START)&& ((usAddress+usNDiscrete) <= (REG_DISCRETE_START + REG_DISCRETE_SIZE))) { for(i=0;i>8)&0x00ff; } } else { eStatus = MB_ENOREG; } return eStatus; } ``` Complete code download?[STM32 driver w5500 transplanting FreeModbus to realize ModbusTCP complete code download](https://download.csdn.net/download/qq_15181569/12264015) Copyright statement: This article is an original article by the blogger and follows the?[CC 4.0 BY-SA](https://creativecommons.org/licenses/by-sa/4.0/)?copyright agreement. Please attach the original source link and this statement for reprinting. --- Source: https://maker.wiznet.io/praveen_k/projects/STM32-drives-w5500-to-port-FreeModbus-to-implement-ModbusTCP/