pom.xml

  <dependency>
            <groupId>com.github.s7connector</groupId>
            <artifactId>s7connector</artifactId>
            <version>2.1</version>
 </dependency>

maven下载不了的，下载包，评论或者私自内免费给
DB212 类：
String类型的我的占用25个字节，要看实际情况

package com.alnan.entity;


import com.github.s7connector.api.annotation.S7Variable;
import com.github.s7connector.impl.utils.S7Type;
import lombok.Data;

import java.io.Serializable;

@Data
public class DB212 implements Serializable {

    @S7Variable(type = S7Type.STRING,byteOffset = 32,bitOffset = 0, size = 25)
    public int PW_plateId;

    @S7Variable(type = S7Type.WORD,byteOffset = 88,bitOffset = 0)
    public int PW_plateLength;

    @S7Variable(type = S7Type.WORD,byteOffset = 92,bitOffset = 0)
    public int PW_plateWidth;

    @S7Variable(type = S7Type.WORD,byteOffset = 208,bitOffset = 0)
    public int PW_send;

    @S7Variable(type = S7Type.WORD,byteOffset = 212,bitOffset = 0)
    public int ACT_PW_1;

    @S7Variable(type = S7Type.WORD,byteOffset = 216,bitOffset = 0)
    public int ACT_PW_2;

    @S7Variable(type = S7Type.WORD,byteOffset = 260,bitOffset = 0)
    public int ACT_HY_UP_1;

    @S7Variable(type = S7Type.WORD,byteOffset = 264,bitOffset = 0)
    public int ACT_HY_DOWN_1;

    @S7Variable(type = S7Type.WORD,byteOffset = 276,bitOffset = 0)
    public int ACT_HY_UP_2;

    @S7Variable(type = S7Type.WORD,byteOffset = 280,bitOffset = 0)
    public int ACT_HY_DOWN_2;

    @S7Variable(type = S7Type.WORD,byteOffset = 292,bitOffset = 0)
    public int ACT_HY_UP_3;

    @S7Variable(type = S7Type.WORD,byteOffset = 296,bitOffset = 0)
    public int ACT_HY_DOWN_3;

    @S7Variable(type = S7Type.WORD,byteOffset = 308,bitOffset = 0)
    public int ACT_HY_UP_4;

    @S7Variable(type = S7Type.WORD,byteOffset = 312,bitOffset = 0)
    public int ACT_HY_DOWN_4;

    @S7Variable(type = S7Type.WORD,byteOffset = 324,bitOffset = 0)
    public int ACT_HY_UP_5;

    @S7Variable(type = S7Type.WORD,byteOffset = 328,bitOffset = 0)
    public int ACT_HY_DOWN_5;

    @S7Variable(type = S7Type.WORD,byteOffset = 340,bitOffset = 0)
    public int ACT_LC_UP_1;

    @S7Variable(type = S7Type.WORD,byteOffset = 344,bitOffset = 0)
    public int ACT_LC_DOWN_1;

    @S7Variable(type = S7Type.WORD,byteOffset = 356,bitOffset = 0)
    public int ACT_LC_UP_2;

    @S7Variable(type = S7Type.WORD,byteOffset = 360,bitOffset = 0)
    public int ACT_LC_DOWN_2;

}

应用：

 //一级发数据
            S7Connector s7Connector = S7ConnectorFactory.buildTCPConnector()
                    .withHost("192.168.100.10")//ip
                    .withPort(102)
                    .withTimeout(1000) //连接超时时间
                    .withRack(0)
                    .withSlot(1)
                    .build();


            s7Connector.write(DaveArea.DB, 212, 32, pzString(plateNo));//212是PLC地址，32是从第多少字节开始写入，
            s7Connector.write(DaveArea.DB,212,88, ByteBuffer.allocate(4).putInt(Integer.valueOf(length)).array());
            s7Connector.write(DaveArea.DB,212,92, ByteBuffer.allocate(4).putInt(Integer.valueOf(width)).array());
            s7Connector.write(DaveArea.DB,212,208, ByteBuffer.allocate(4).putInt(1).array());
            System.out.println(s7Serializer.dispense(DB212.class,212,0));
            s7Connector.close();



 public byte[] pzString(String out_string){
        //        写入字符串
        //第一个参数：DaveArea.DB 表示读取PLC的地址区域为DB
        //第二个参数：DB块地址，若plc中是DB1000，则填1000
        //第三个参数：偏移量
        //第四个参数：写入的数据 二进制数组byte[]  ,总长度为10的话，有效数据只能是10-8，第一位代表总长，第二位，代表有效数据字节
        int writeStrLength = 25;//地址块大小
        byte[] writeBytes = new byte[writeStrLength];
        writeBytes[0] = (byte) writeStrLength;//写入本字符串块总宽度
        out_string = out_string.trim();//清除掉两边的空串
        int availableEffectCharLength = 0;//有效字符数控制
        if (out_string.length() > writeStrLength - 2) {//>writeStrLength-2 截断到最大有效数据位
            availableEffectCharLength = writeStrLength - 2;

        } else {//<=writeStrLength-2
            availableEffectCharLength = out_string.length();
        }
        writeBytes[1] = (byte) availableEffectCharLength;//写入有效字节数
        byte[] strBytes = out_string.getBytes(StandardCharsets.US_ASCII);
        for (int i = 0; i < availableEffectCharLength; i++) {
            writeBytes[i + 2] = strBytes[i];
        }
      return writeBytes;
    }

基本上能用起来了
具体细节：

https://blog.csdn.net/qq_51383028/article/details/140549849