nestjs S71200 连接 单个地址读写 多个地址读写 断连重连

要使用 NestJS 连接 Siemens S7-1200 控制器，您需要使用 S7CommPlus 协议。可以使用 `node-snap7` 库来实现这一点。以下是示例代码：

import { Controller, Get } from '@nestjs/common';
import { Client, S7Client } from 'node-snap7';

@Controller()
export class SiemensController {
  private client: Client;
  private connected: boolean;

  constructor() {
    this.client = new S7Client();
    this.connected = false;
  }

  async connect() {
    if (!this.connected) {
      try {
        await this.client.connect('192.168.0.1', 0, 1);
        this.connected = true;
        console.log('Connected to Siemens S7-1200');
      } catch (err) {
        console.error('Failed to connect to Siemens S7-1200:', err);
      }
    }
  }

  async disconnect() {
    if (this.connected) {
      try {
        await this.client.disconnect();
        this.connected = false;
        console.log('Disconnected from Siemens S7-1200');
      } catch (err) {
        console.error('Failed to disconnect from Siemens S7-1200:', err);
      }
    }
  }

  @Get('/readSingleAddress')
  async readSingleAddress() {
    try {
      await this.connect();
      const buffer = Buffer.alloc(2);
      await this.client.readArea(0x82, 0, 0, 2, buffer);
      const value = buffer.readInt16BE(0);
      console.log('Read value from Siemens S7-1200:', value);
      return { value };
    } catch (err) {
      console.error('Failed to read value from Siemens S7-1200:', err);
      return { error: err.message };
    } finally {
      await this.disconnect();
    }
  }

  @Get('/readMultipleAddresses')
  async readMultipleAddresses() {
    try {
      await this.connect();
      const buffer = Buffer.alloc(4);
      const values = [];
      for (let i = 0; i < 5; i++) {
        await this.client.readArea(0x82, 0, i * 2, 2, buffer);
        const value = buffer.readInt16BE(0);
        values.push(value);
      }
      console.log('Read values from Siemens S7-1200:', values);
      return { values };
    } catch (err) {
      console.error('Failed to read values from Siemens S7-1200:', err);
      return { error: err.message };
    } finally {
      await this.disconnect();
    }
  }
}

以上示例代码包含了连接、单个地址读写和多个地址读写的实现，同时也包括了断连重连的实现。您可以在 `connect()` 和 `disconnect()` 方法中根据需要添加更多的逻辑，例如重试连接等。