lxCameraApi/src/main/java/com/example/lxcameraapi/S7WriteTest.java

package com.example.lxcameraapi;

import com.sourceforge.snap7.moka7.S7;
import com.sourceforge.snap7.moka7.S7Client;

import java.time.LocalDateTime;

/**
 * S7 PLC 数据写入测试工具
 */
public class S7WriteTest {

    // PLC连接参数
    private static final String IP = "127.0.0.1";
    private static final int RACK = 0;
    private static final int SLOT = 2;
    private static final int DB_NUMBER = 1;

    public static void main(String[] args) {
        S7Client client = new S7Client();

        try {
            // 连接PLC
            int result = client.ConnectTo(IP, RACK, SLOT);
            if (result != 0) {
                System.out.println("连接PLC失败，错误码: " + result);
                return;
            }
            System.out.println("连接PLC成功");

            // 写入数据
            writePlcData(client);

            System.out.println("写入完成");
        } catch (Exception e) {
            System.out.println("异常: " + e.getMessage());
            e.printStackTrace();
        } finally {
            client.Disconnect();
        }
    }

    private static void writePlcData(S7Client client) {
        byte[] buffer = new byte[100];
        LocalDateTime now = LocalDateTime.now();
        String date = now.format(java.time.format.DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));

        // 托盘号 String[50] (偏移0，长度52字节，含2字节长度前缀)
        writeS7String(buffer, 0, 50, "TRAY-20260427-"+date);

        // 批次号 String[20] (偏移52，长度22字节)
        writeS7String(buffer, 52, 20, "BATCH-ABC123");

        // 日期 String[20] (偏移74，长度22字节)
        writeS7String(buffer, 74, 20, "2026-04-27 10:30:00");

        // 拍照标志 byte (偏移96)
        buffer[96] = 1;

        // 拍照结果 byte (偏移97)
        buffer[97] = 0;

        // 写入PLC (从偏移0开始，写入98字节)
        int writeResult = client.WriteArea(S7.S7AreaDB, DB_NUMBER, 0, buffer.length, buffer);
        if (writeResult == 0) {
            System.out.println("写入成功");
        } else {
            System.out.println("写入失败，错误码: " + writeResult);
        }
    }

    /**
     * 写入S7 String格式
     * @param buffer  目标缓冲区
     * @param offset  偏移量
     * @param maxLen  最大长度
     * @param value   要写入的字符串
     */
    private static void writeS7String(byte[] buffer, int offset, int maxLen, String value) {
        // S7 String格式: [0]=最大长度, [1]=实际长度, [2+]=字符串内容
        buffer[offset] = (byte) maxLen;
        byte[] valueBytes = value.getBytes();
        byte actualLen = (byte) Math.min(valueBytes.length, maxLen);
        buffer[offset + 1] = actualLen;

        // 复制字符串内容
        for (int i = 0; i < actualLen; i++) {
            buffer[offset + 2 + i] = valueBytes[i];
        }
        // 剩余部分填充空格
        for (int i = actualLen; i < maxLen; i++) {
            buffer[offset + 2 + i] = ' ';
        }
    }
}