3BSE018059R1 TC512V1 工控系统自动化备
示例程序假设用户
希望将Modbus TCP I/O机架初始化为Mint启动模块的一部分（即在主Mint程序执行之前）。因为没有与启动模块关联的ONERROR事件，所以示例应用程序使用Mint Shutdown块来检测启动例程中的错误。关机代码检测Modbus I/O初始化期间是否发生错误，如果发生错误，则会尝试重新启动程序10次，然后最终放弃并让程序终止。这对于驱动器与Modbus TCP I/O通信，然后独立复位的情况是必要的。如果驱动器重新启动的时间少于上一次Modbus连接关闭所需的时间，则可能会发生错误，因此代码提供了一种重试机制，该机制至少持续最长连接超时时间（30秒）。
电源循环
如果Modbus I/O机架独立进行电源循环，则最终可能需要等待驱动器重置其TCP连接（约2分钟超时）。ParentTask还包括一行代码，确保只有在初始化例程中定义了机架和模块时才执行ModbusIO任务。在大多数情况下，如果根本没有远程I/O，则不会使用示例代码，但如果用户希望包含所有代码，以便在将来某个时候添加扩展I/O模块，则会包含此检查。如果ModbusIO:：nNoOfRacks>0，则运行（ModbusIO）如果在故障条件下使用监控超时来触发数字/模拟输出行为（例如自动关闭输出），请注意模块将因通信延迟而超时，而不仅仅是连接中的物理断开。因此，例如，由于Mint程序跳到（并处于）Mint事件或下载新的Mint程序而暂停ModbusIO任务的执行可能会导致输出被迫进入“故障行为”状态。
The sample program assumes that the user
You want to initialize the Modbus TCP I/O rack as part of the Mint boot module (that is, before the main Mint program is executed). Because there is no ONERROR event associated with the boot module, the sample application uses the Mint Shutdown block to detect errors in the boot routine. The shutdown code detects whether an error occurs during Modbus I/O initialization. If an error occurs, it will try to restart the program 10 times, and then finally give up and let the program terminate. This is necessary when the driver communicates with Modbus TCP I/O and then resets independently. If the drive restarts for less than the last time the Modbus connection was closed, an error may occur, so the code provides a retry mechanism that lasts at least the longest connection timeout (30 seconds).
Power cycle
If the Modbus I/O rack cycles power independently, you may eventually need to wait for the drive to reset its TCP connection (about a 2-minute timeout). ParentTask also includes a line of code to ensure that ModbusIO tasks are executed only when racks and modules are defined in the initialization routine. In most cases, if there is no remote I/O at all, the sample code will not be used, but if the user wants to include all the code to add an extended I/O module at some time in the future, this check will be included. If ModbusIO:: nNoOfRacks>0, run (ModbusIO) If monitoring timeout is used to trigger digital/analog output behavior (such as automatic shutdown of output) under fault conditions, please note that the module will timeout due to communication delay, not just physical disconnection in connection. Therefore, for example, suspending the execution of the ModbusIO task because the Mint program jumps to (and is in) a Mint event or downloads a new Mint program may cause the output to be forced into a "fault behavior" state.
