一、背景

在一般场景下，只需一路IO连接，但稍微复杂的场景，就需要不同通讯周期的连接，这就需要有多组IO连接。

而大于一组的连接调试方法是一样的，因此主要解决2组连接的代码开发。

二、可行性验证

在Eip Scanner Demo（主站）、PLC（从站）软件上分别配置两个生产者连接，验证其数据收发可行性及稳定性。得到视频及报文如下：

1、Enip

2、ForwardOpen 1

3、ForwardOpen 2

4、ForwardCloes 2

5、ForwardCloes 1

可见，进行了两次ForwardOpen，建立了两个生产者连接。

由上文可见，两个生产者连接的ForwardOpen的不同点在于:

1、Connection Path 由PLC自动生成，直接配置到Ubuntu中

2、Connecte Serial Number 自由选择，只要是两个连接不同即可，见协议原文

3、Connection Parameter (可选，如果两个收发字节数相同，则此项也相同)

因此，便可满足上述要求情况下，将多生产者连接集成到一个SDK中。

但需要注意多线程下的单一物理网口的数据抢占问题。

三、开发调试

发现在_connectionMap中管理了所有的IO连接。

在forwardopen阶段注册_connectionMap，每开一个IO连接都会注册一个_connectionMap进去

在handleConnections中，若IO连接不存在，则删除掉

而在代码中，无需在两个连接的情况下守护两个connectionManager，于是更改代码如下：

int main() {。。。。parameters.o2tRealTimeFormat = true;parameters.t2oRealTimeFormat = true;parameters.originatorVendorId = 0xaa;parameters.connectionTimeoutMultiplier=2;parameters.priorityTimeTick=10;parameters.t2oNetworkConnectionParams |= NetworkConnectionParams::P2P;parameters.t2oNetworkConnectionParams |= NetworkConnectionParams::SCHEDULED_PRIORITY;parameters.t2oNetworkConnectionParams |= 0; //size of Assm100 =1parameters.o2tNetworkConnectionParams |= NetworkConnectionParams::P2P;parameters.o2tNetworkConnectionParams |= NetworkConnectionParams::SCHEDULED_PRIORITY;parameters.o2tNetworkConnectionParams |= 4; //size of Assm100 =1parameters.originatorSerialNumber = 0x012345;parameters.o2tRPI = 50000;parameters.t2oRPI = 50000;//50msparameters.transportTypeTrigger |= NetworkConnectionParams::CLASS1;parameters.transportTypeTrigger |= NetworkConnectionParams::TRIG_CYCLIC;  std::chrono::milliseconds timeout(5000);
//connect oneauto si_1 = std::make_shared<SessionInfo>("192.168.2.88", 0xAF12,timeout,50000);ConnectionManager connectionManager_1;parameters.connectionPath = {0x20, 0x04,0x24, 0x01, 0x2C, 0x65, 0x2C, 0xFF}; parameters.connectionSerialNumber = 0xbebc;auto io_1 = connectionManager_1.forwardOpen(si_1, parameters);if (auto ptr = io_1.lock()) {ptr->setDataToSend(std::vector<uint8_t>(4));ptr->setReceiveDataListener([](auto realTimeHeader, auto sequence, auto data) {std::ostringstream ss;ss << "secNum=" << sequence << " data=";for (auto &byte : data) {ss << "[" << std::hex << (int) byte << "]";}Logger(LogLevel::INFO) << "Received: " << ss.str();});ptr->setCloseListener([]() {Logger(LogLevel::INFO) << "Closed";});}//connect twoauto si_2 = std::make_shared<SessionInfo>("192.168.2.88", 0xAF12,timeout,50050);//ConnectionManager connectionManager_2;parameters.connectionPath = {0x20, 0x04,0x24, 0x01, 0x2C, 0x64, 0x2C, 0x6E}; parameters.connectionSerialNumber = 0x275D;//auto io_2 = connectionManager_2.forwardOpen(si_2, parameters);auto io_2 = connectionManager_1.forwardOpen(si_2, parameters);if (auto ptr = io_2.lock()) {ptr->setDataToSend(std::vector<uint8_t>(4));ptr->setReceiveDataListener([](auto realTimeHeader, auto sequence, auto data) {std::ostringstream ss;ss << "secNum=" << sequence << " data=";for (auto &byte : data) {ss << "[" << std::hex << (int) byte << "]";}Logger(LogLevel::INFO) << "Received: " << ss.str();});ptr->setCloseListener([]() {Logger(LogLevel::INFO) << "Closed";});}//handle connectwhile (connectionManager_1.hasOpenConnections()) {connectionManager_1.handleConnections(std::chrono::milliseconds(50));// connectionManager_2.handleConnections(std::chrono::milliseconds(50));}connectionManager_1.forwardClose(si_1, io_1);connectionManager_1.forwardClose(si_2, io_2);。。。。return EXIT_SUCCESS;
}

显示Log如下，能正常维持两个连接