Android plc通信
Posted LZ涸泽而渔
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android/信捷plc modbus-ASCII串口通信
终于有时间总结一下用到的技术了，之前忙得狗血淋头，搞这个plc弄到自闭，由于没有百度到任何案例，遂自己花大量的精力给弄出来并应用到运营项目中，给予各位参考
modbus协议封装
modbus是一种通讯规约，简单的来说，由起始符、帧头、寄存器命令、LRC校验、结束符等组成，此文中，modbus主要用于和信捷plc通讯，采用ascll编码方式（RTU类似，自行修改代码中转码部分即可），另外，因为是规约，所以得需要与你的上位机PLC一起对接，例如本文中规约为：寄存器地址长度为4-“0001”,通讯命令长度为1-“1”,意味着，像寄存器0001发送数据1，来完成对应的操作。
modbus封装类：
public class PlcModBusUtil
//起始符
private final String START = "3A";
//帧头
private final String FRAME_HEADER = "3032";
//写多个寄存器命令
private final String WRITE_COMMAND = "3130";
//写单个寄存器
private final String WRITE_SIGNLE_COMMAND = "3036";
//读命令
private final String READ_COMMAND = "3033";
//结束符
private final String END = "0D0A";
public static final String TAG = "PlcModBusUtil";
/**
* 封装modbus，写请求协议
*
* @return
*/
public String getWriteString(String address, String[] data)
StringBuilder stringBuilder = new StringBuilder();
//起始符
stringBuilder.append(START);
//帧头
stringBuilder.append(FRAME_HEADER);
//功能码
if (data.length > 1)
stringBuilder.append(WRITE_COMMAND);
else
stringBuilder.append(WRITE_SIGNLE_COMMAND);
//地址,多个地址，只传起始地址，16进制转ascii
stringBuilder.append(hexToAscii(address));
//多个地址与数据，需要添加长度和位数
if (data.length>1)
//长度,例如：写2条数据，长度为2，位数为4，长度补足4位，位数补足2位
StringBuilder lengthBuilder = new StringBuilder();
lengthBuilder.append(data.length);
int length = lengthBuilder.length();
for (int i = 0; i < 4 - length; i++)
lengthBuilder.insert(0, "0");
//转ascii
stringBuilder.append(hexToAscii(lengthBuilder.toString()));
//位数
StringBuilder digitsBuilder = new StringBuilder();
digitsBuilder.append(data.length * 2);
int digitsLength = digitsBuilder.length();
for (int i = 0; i < 2 - digitsLength; i++)
digitsBuilder.insert(0, "0");
//转ascii
stringBuilder.append(hexToAscii(digitsBuilder.toString()));
//写入数据处理
for (String datum : data)
//10进制转16进制
StringBuilder hexString = new StringBuilder();
hexString.append(datum);
int hexLength = hexString.length();
//转化后的16进制进行补位，目标为4位
for (int i = 0; i < 4 - hexLength; i++)
hexString.insert(0, "0");
//转ascii，添加数据
stringBuilder.append(hexToAscii(hexString.toString()));
//LRC校验结果生成，去掉起始
stringBuilder.append(getLrc(stringBuilder.substring(START.length())));
//添加结束符
stringBuilder.append(END);
return stringBuilder.toString();
public String getReadString(String[] address)
StringBuilder stringBuilder = new StringBuilder();
//起始符
stringBuilder.append(START);
//帧头
stringBuilder.append(FRAME_HEADER);
//读命令
stringBuilder.append(READ_COMMAND);
//地址，多个地址，只传起始地址,16进制转ascii
stringBuilder.append(hexToAscii(address[0]));
//长度,例如：写读条数据，长度为2,长度补足4位 位数为4，位数补足2位
StringBuilder lengthBuilder = new StringBuilder();
lengthBuilder.append(address.length);
int length = lengthBuilder.length();
for (int i = 0; i < 4 - length; i++)
lengthBuilder.insert(0, "0");
//转ascii
stringBuilder.append(hexToAscii(lengthBuilder.toString()));
//LRC校验结果生成，去掉起始
stringBuilder.append(getLrc(stringBuilder.substring(START.length())));
//添加结束符
stringBuilder.append(END);
return stringBuilder.toString();
//返回，是否是读请求的返回数据
public boolean isReadRequest(String readString)
if (readString.length() < 30)
System.out.println("收到的数据响应格式不正确");
return false;
String startString = START + FRAME_HEADER;
String command = readString.substring(startString.length(), startString.length()+READ_COMMAND.length() );
return command.equals(READ_COMMAND);
public String[] formatReadString(String readString)
String startString = START + FRAME_HEADER + READ_COMMAND;
if (readString.startsWith(startString))
if (readString.length() < 30)
System.out.println("收到的数据响应格式不正确");
return null;
String contentString = readString.substring(startString.length() + 4, readString.length() - 8);
//数据为8位一组
if (contentString.length() % 8 != 0)
System.out.println("收到的数据响应格式不正确");
return null;
int length = contentString.length() / 8;
String[] contentArray = new String[length];
for (int i = 0; i < length; i++)
//8位结果
String data = contentString.substring(i * 8, i * 8 + 8);
//ascii转16进制
String hexString = asciiToHex(data);
//16进制转10进制
contentArray[i] = num16to10(hexString) + "";
return contentArray;
Flog.e(TAG, "无效数据");
return null;
private String getLrc(String hexdata)
StringBuilder rtu = new StringBuilder();
int dealLength = hexdata.length() / 2;
for (int i = 0; i < dealLength; i++)
String stringAscill = hexdata.substring(2 * i, 2 * i + 2);
rtu.append(Integer.parseInt(stringAscill) - 30);
int rtuLength = rtu.length() / 2;
int sum = 0;
for (int i = 0; i < rtuLength; i++)
sum += Integer.parseInt(rtu.substring(2 * i, 2 * i + 2), 16);
//求和结果，补位成4位
StringBuilder sumBuilder = new StringBuilder();
sumBuilder.append(num10to16(sum).toUpperCase());
int sumBuilderLength = sumBuilder.length();
for (int i = 0; i < 4 - sumBuilderLength; i++)
sumBuilder.insert(0, "0");
//补为4位的 只取低位
String result = sumBuilder.substring(2, sumBuilder.length());
return hexToAscii(num10to16(Integer.parseInt("100", 16) - Integer.parseInt(result, 16)).toUpperCase());
private String hexInt(int total)
int a = total / 256;
int b = total % 256;
if (a > 255)
return hexInt(a) + format(b);
return format(a) + format(b);
private String format(int hex)
String hexa = Integer.toHexString(hex);
int len = hexa.length();
if (len < 2)
hexa = "0" + hexa;
return hexa;
/**
* 10进制转16进制
*
* @param num
* @return
*/
private String num10to16(Integer num)
return Integer.toHexString(num);
/**
* 16进制转10进制
*/
private int num16to10(String hexString)
int result = 0;
try
result = new BigInteger(hexString, 16).intValue();
catch (Exception e)
Flog.e(TAG, "数据解析失败");
return result;
/**
* 16进制转ascii
*
* @param hex
* @return
*/
public String hexToAscii(String hex)
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < hex.length(); i++)
char a = hex.charAt(i);
int aInt = (int) a;
stringBuilder.append(num10to16(aInt));
return stringBuilder.toString();
/**
* ascii转16进制
*
* @param str
* @return
*/
private String asciiToHex(@NotNull String str)
byte[] hex = fromHex(str);
StringBuilder result = new StringBuilder();
for (byte b : hex)
result.append((char) b);
return result.toString();
/**
* 字节数组转16进制
*
* @param bytes
* @return
*/
public String toHex(byte[] bytes)
StringBuilder sb = new StringBuilder(bytes.length * 2);
byte[] arr = bytes;
int len = bytes.length;
for (int i = 0; i < len; ++i)
byte b = arr[i];
sb.append(String.format("%02x", b));
return sb.toString().toUpperCase();
/**
* string转16进制字节数组
*
* @param string
* @return
*/
public byte[] fromHex(String string)
byte[] result = new byte[string.length() / 2];
for (int i = 0; i < result.length; ++i)
try
result[i] = (byte) Integer.parseInt(string.substring(i * 2, i * 2 + 2), 16);
catch (Exception e)
Flog.e(TAG, "数据解析失败");
return result;
/**
* hex字符串转byte数组
*
* @param inHex 待转换的Hex字符串
* @return 转换后的byte数组结果
*/
public byte[] hexToByteArray(String inHex)
int hexlen = inHex.length();
byte[] result;
if (hexlen % 2 == 1)
//奇数
hexlen++;
result = new byte[(hexlen / 2)];
inHex = "0" + inHex;
else
//偶数
result = new byte[(hexlen / 2)];
int j = 0;
for (int i = 0; i < hexlen; i += 2)
result[j] = hexToByte(inHex.substring(i, i + 2));
j++;
return result;
/**
* Hex字符串转byte
*
* @param inHex 待转换的Hex字符串
* @return 转换后的byte
*/
public byte hexToByte(String inHex)
return (byte) Integer.parseInt(inHex, 16);
/**
* 字节数组转16进制
*
* @param bytes 需要转换的byte数组
* @return 转换后的Hex字符串
*/
public String bytesToHex(byte[] bytes)
StringBuffer sb = new StringBuffer();
for (int i = 0; i < bytes.length; i++)
String hex = Integer.toHexString(bytes[i] & 0xFF);
if (hex.length() < 2)
sb.append(0);
sb.append(hex);
return sb.toString();
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