modbus

I am very new to Modbus and PyModBus however I have spent a good amount of time trying to read up and experiment with it. If anyone could point me in the right direction I would appreciate it... I have a drive with distance, velocity, acceleration, and deceleration on registers 40001, 40003, 40005, and 40007 (respectively). I was initially able to write to the distance register, using client.write_register(0000, n). After trying to write to velocity the drive started going haywire and faulting, and spinning 10x as fast as it should've been. However, the real priority is reading registers. I am

I have this byte array: static byte[] buf = new byte[] { (byte) 0x01, (byte) 0x04, (byte)0x00, (byte)0x01,(byte)0x00, (byte) 0x01}; Now, the CRC checksum of this byte array is supposed to be 0x60, 0x0A. I want the Java code to recreate this checksum, however I cant seem to recreate it. I have tried crc16: static int crc16(final byte[] buffer) { int crc = 0xFFFF; for (int j = 0; j < buffer.length ; j++) { crc = ((crc >>> 8) | (crc << 8) )& 0xffff; crc ^= (buffer[j] & 0xff);//byte to int, trunc sign crc ^= ((crc & 0xff) >> 4); crc ^= (crc << 12) & 0xffff; crc ^= ((crc & 0xFF) << 5) & 0xffff; }

一、测试样式 二、读写范围函数（一次最多取125个地址） public void ModbusSerialRtuMasterWriteRegisters() { using (TcpClient tcp_wg = new TcpClient(wg_ip, Convert.ToInt32(wg_port))) { //slaveId地址，默认1 byte slaveId = Convert.ToByte(this.txt_slave.Text); //读取开始地址 ushort startAddress = Convert.ToUInt16(this.txt_start.Text); //读取数据范围，可以多范围数据读取 ushort number = Convert.ToUInt16(this.txt_number.Text); //写入起始地址，此函数同时可读写，同时进行，先写后读 ushort writeAddress = Convert.ToUInt16(this.txt_write_start.Text); //写入数据内容，实例写入三个数据 ushort[] registers = new ushort[] { 5, 2, 3 }; //创建TCP通讯 my_wg = ModbusIpMaster.CreateIp(tcp_wg); //单独进行写函数 //my_wg

I' trying to connect from my Mac laptop to a Modbus device ( MR-SI4 ) using a serial connection using a USB RS485 converter that gets "mounted" to /dev/cu.SLAB_USBtoUART . This is my code: import logging logging.basicConfig() log = logging.getLogger() log.setLevel(logging.DEBUG) from pymodbus.constants import Endian from pymodbus.constants import Defaults from pymodbus.payload import BinaryPayloadDecoder from pymodbus.client.sync import ModbusSerialClient as ModbusClient from pymodbus.transaction import ModbusRtuFramer # settings for USB-RS485 adapter SERIAL = '/dev/cu.SLAB_USBtoUART' BAUD =

看下效果图 ModBus通讯协议 方法名 作用 所需参数 返回值 对应功能码 ReadCoils 读取DO的状态 从站地址(8位) byte slaveAddress 起始地址(16位) ushort startAddress 读取数量(16位) ushort numberOfPoints bool[] 01 ReadInputs 读取DI的状态 从站地址(8位) byte slaveAddress 起始地址(16位) ushort startAddress 读取数量(16位) ushort numberOfPoints bool[] 02 ReadHoldingRegisters 读取AO的值 从站地址(8位) byte slaveAddress 起始地址(16位) ushort startAddress 读取数量(16位) ushort numberOfPoints ushort[] 03 ReadInputRegisters 读取AI的值 从站地址(8 位) byte slaveAddress 起始地址(16位) ushort startAddress 读取数量(16位) ushort numberOfPoints ushort[] 04 WriteSingleCoil 写入值到DO 从站地址(8位) byte slaveAddress 线圈地址(16位) ushort