成都网站建设哪家技术好,三门峡建设环境局网站,盐城网站建设策划方案,如何建一个企业网站监测数据采集物联网应用开发步骤(9.2)
Modbus rtu协议开发
本章节在《监测数据采集物联网应用开发步骤(7)》基础上实现可参考《...开发步骤(7)》调试工具#xff0c;本章节代码需要调用modbus_tk组件#xff0c;阅读本章节前建议baidu熟悉modbus rtu协议内容
组件安装modb…监测数据采集物联网应用开发步骤(9.2)
Modbus rtu协议开发
本章节在《监测数据采集物联网应用开发步骤(7)》基础上实现可参考《...开发步骤(7)》调试工具本章节代码需要调用modbus_tk组件阅读本章节前建议baidu熟悉modbus rtu协议内容
组件安装modbus_tk
pip3 install modbus_tk
验证是否安装成功python中运行下列代码无异常则安装成功
import modbus_tk 新建modbus协议管理类com.zxy.comport.ComModBus.py
#! python3
# -*- coding: utf-8 -Created on 2020年05月10日
author: zxyong 13738196011import time,struct
from com.zxy.common import Com_Para
from com.zxy.common.Com_Fun import Com_Fun
from com.zxy.z_debug import z_debug
import modbus_tk.defines as cst
import modbus_tk.modbus_rtu as modbus_rtu#监测数据采集物联网应用--modbus协议管理类
class ComModBus(z_debug):def __init__(self):passstaticmethoddef get_objAryRtuMaster(inputComPort): master Com_Fun.GetHashTableNone(Com_Para.objAryRtuMaster, inputComPort)if master is None:com_at Com_Fun.GetHashTableNone(Com_Para.htComPort, inputComPort)if com_at is not None:master modbus_rtu.RtuMaster(com_at.attSerial) # 设定串口为从站master.set_timeout(5.0)master.set_verbose(True)Com_Fun.SetHashTable(Com_Para.objAryRtuMaster, inputComPort, master)return master#字符串转16进制字节并crc16校验传入参数无crc校验staticmethoddef get_data_com_nocrc(inputComPort, CmdStr): temReturn None try: com_at Com_Fun.GetHashTable(Com_Para.htComPort, inputComPort) inputByte bytes().fromhex(CmdStr)inputByte inputByte ComModBus._getCrc16(inputByte)if com_at.WritePortData(inputByte) 0:temReturn com_at.attReturnValue com_at.attReturnValue Noneexcept Exception as e:temReturn Nonereturn temReturn#字符串转字节发送,ascii发送staticmethoddef get_data_com_ascii(inputComPort, CmdStr): temReturn None try: com_at Com_Fun.GetHashTable(Com_Para.htComPort, inputComPort)inputByte bytes(CmdStr, encodingutf8)if com_at.WritePortDataImmed(inputByte) 0:temReturn com_at.attReturnValue com_at.attReturnValue Noneexcept Exception as e:temReturn Nonereturn temReturn#字符串转16进制字节发送staticmethoddef get_data_com_hex(inputComPort, CmdStr): temReturn None try:com_at Com_Fun.GetHashTable(Com_Para.htComPort, inputComPort) inputByte bytes().fromhex(CmdStr)if com_at.WritePortData(inputByte) 0:comValue com_at.attReturnValueif comValue is None:return NonetemReturn comValuecom_at.attReturnValue Noneexcept Exception as e:temReturn Nonereturn temReturn#字节发送staticmethoddef get_data_com_byte(inputComPort, inputByte): temReturn None try:com_at Com_Fun.GetHashTable(Com_Para.htComPort, inputComPort) if com_at.WritePortData(inputByte) 0:comValue com_at.attReturnValueif comValue is None:return NonetemReturn comValuecom_at.attReturnValue Noneexcept Exception as e:temReturn Nonereturn temReturn#Modbus 04功能码发送staticmethoddef get_data_rtu_04(inputComPort, inputModbusAddr, inputModbusBegin, inputModbusLength):red []try:master ComModBus.get_objAryRtuMaster(inputComPort)if master is not None:red master.execute(int(inputModbusAddr), cst.READ_INPUT_REGISTERS, int(inputModbusBegin), int(inputModbusLength)) # 这里可以修改需要读取的功能码 time.sleep(0.1) if isinstance(red, list) or isinstance(red, tuple): return redelse:return []except Exception as e:return []#Modbus 03功能码发送 staticmethoddef get_data_rtu_03(inputComPort, inputModbusAddr, inputModbusBegin, inputModbusLength):read []try:master ComModBus.get_objAryRtuMaster(inputComPort)if master is not None:read master.execute(inputModbusAddr, cst.READ_HOLDING_REGISTERS, inputModbusBegin, inputModbusLength) # 这里可以修改需要读取的功能码 time.sleep(0.1) if isinstance(read, list) or isinstance(read, tuple): return readelse:return []except Exception as e:return []#Modbus 写寄存器数据staticmethoddef set_data_rtu(inputComPort, inputModbusAddr, inputModbusBegin, inputValue):read []try:master ComModBus.get_objAryRtuMaster(inputComPort)if master is not None:# 这里可以修改需要读取的功能码 if isinstance(inputValue, list) or isinstance(read, tuple):read master.execute(inputModbusAddr, cst.WRITE_MULTIPLE_REGISTERS, inputModbusBegin, output_valueinputValue) else:read master.execute(inputModbusAddr, cst.WRITE_SINGLE_REGISTER, inputModbusBegin, output_valueinputValue) if isinstance(read, list) or isinstance(read, tuple): return readelse:return []except Exception as e:return []staticmethoddef set_data_rtu2(inputComPort, inputModbusAddr, inputModbusBegin, inputValue):read []try:master ComModBus.get_objAryRtuMaster(inputComPort)if master is not None:# 这里可以修改需要读取的功能码 if isinstance(inputValue, list) or isinstance(read, tuple):read master.execute(inputModbusAddr, cst.ANALOG_INPUTS, inputModbusBegin, output_valueinputValue) else:read master.execute(inputModbusAddr, cst.ANALOG_INPUTS, inputModbusBegin, output_valueinputValue) if isinstance(read, list) or isinstance(read, tuple): return readelse:return []except Exception as e:return []staticmethoddef _getCrc16(RtuStr):b 0xA001# 16位寄存器a 0xFFFFfor byte in RtuStr:# 1、把数据帧中的第一个8位字节与CRC寄存器中的低字节进行异或运算a a ^ bytefor i in range(8):# 3、如果最低位为1将CRC寄存器与一个预设的固定值0A001H进行异或运算if a 0x0001:a a 1a a ^ b # 2、将CRC寄存器向右移一位最高位填以0最低位移出并检测else:a a 1aa 0 * (6 - len(hex(a))) hex(a)[2:]# 获取低和高位lo, hh int(aa[:2], 16), int(aa[2:], 16)hexbytes bytes([hh, lo])return hexbytes#高低位 reverse: true高位在前 false低位在前staticmethoddef ReadFloat(n1, n2, reverseFalse): n %04x % n1m %04x % n2if reverse:v n melse:v m ny_bytes bytes.fromhex(v)y struct.unpack(!f, y_bytes)[0]y round(y, 6)return ystaticmethoddef WriteFloat(value, reverseFalse):y_bytes struct.pack(!f, value)y_hex .join([%02x % i for i in y_bytes])n, m y_hex[:-4], y_hex[-4:]n, m int(n, 16), int(m, 16)if reverse:v [n, m]else:v [m, n]return vstaticmethoddef ReadDint(n1,m1, reverseFalse):n %04x % n1m %04x % m1if reverse:v n melse:v m ny_bytes bytes.fromhex(v)y struct.unpack(!i, y_bytes)[0]return ystaticmethoddef WriteDint(value, reverseFalse):y_bytes struct.pack(!i, value)y_hex .join([%02x % i for i in y_bytes])n, m y_hex[:-4], y_hex[-4:]n, m int(n, 16), int(m, 16)if reverse:v [n, m]else:v [m, n]return vmodbus rtu测试案例MonitorDataCmd.py主文件中编写
from com.zxy.comport.ComModBus import ComModBus
在 if __name__ __main__:下添加 #串口配置参数Com_Para.ComPortList COM2,9600,8,0,A;COM4,9600,8,2,B#串口连接初始化Init_Page.Start_ComPort()#Modbus-rtu协议功能测试temA01modbus ComModBus()#利用modbus_tk组件获取数据参数:COM索引,modbus站地址,modbus起始位,modbus长度read temA01modbus.get_data_rtu_03(A,1,0,10)print(获取10进制原始返回值str(read))modValue []iIndex 0.0n1 0n2 0for temSV in read:if iIndex % 2 ! 0:n2 int(temSV)#16进制单精转浮点temMV temA01modbus.ReadFloat(n1,n2,True)modValue.append(temMV)else:n1 int(temSV)iIndex iIndex 1print(获取读到并解析的寄存器浮点数str(modValue))#利用modbus指令协议直接通过com口读取数据temCmd 010300A1000A942Fbhex temA01modbus.get_data_com_hex(A,temCmd)read str(binascii.b2a_hex(bhex).decode(Com_Para.U_CODE)).upper()print(获取16进制返回值str(read))
运行测试结果如下图: 测试案例中例举了2种方法都可以读到数据任取其一即可。
针对
#利用modbus指令协议直接通过com口读取数据 temCmd 010300A1000A942F
指令解释如下:
01 站地址
03 功能码
00A1 寄存器开始地址(16进制)
000A 读取数据长度10个(16进制转10进制)
942F CRC校验码
获取16进制返回值010314429DA8F643060A3D420070A44343000043554CCD49A8返回值解释如下:
01 站地址
03 功能码
14 数据长度20(16进制转10进制)
429DA8F643060A3D420070A44343000043554CCD 数据值16进制
49A8 CRC校验码
429DA8F643060A3D420070A44343000043554CCD 数据值解析要依据相关对方开发说明文档假设该数据为寄存器浮点数则按如下解析
429D A8F6 10进制浮点数 78.83
4306 0A3D 10进制浮点数 134.039
4200 70A4 10进制浮点数 32.11
4343 0000 10进制浮点数 195
4355 4CCD 10进制浮点数 213.300
可以利用该工具计算IEEE 754浮点数十六进制相互转换(32位,四字节,单精度)
在线进制转换-IEE754浮点数16进制转换
