如果在视觉应用程序中将 "TriggerDelay "配置为 "NetTime"，则必须注意网络时间（例如摄像机模块的 PLK 接口）与控制器的本地系统时间之间可能存在时间偏移。
在 mapp Vision HMI 应用程序中，由于通过 HMI 应用程序触发的图像采集的网络时间计算会失真，因此这种时间偏移会导致图像采集变得越来越慢，离控制器上次重启的时间也越来越远。mapp Vision HMI 应用程序中的图像触发延迟与时间偏移成正比（诊断数据点 NettimeOffset）。摄像机与控制器之间的其他通信（如保存和加载视觉应用程序）不会受到影响。
时间偏移也会对用户应用程序产生影响。
建议让控制器与 POWERLINK 网络同步工作。为此，应在控制器配置中将系统定时器的源配置为相应的接口。有关配置定时行为的其他信息，请参阅自动化帮助中的CPU 属性 - 定时特性一节。
图在控制器配置中，将 "系统计时器 "配置为所用接口，以便将控制器的本地系统时间与接口同步。
If "TriggerDelay" is configured to "NetTime" in the vision application, it is important to note that there may be a time offset between the network time (e.g. PLK interface of the camera module) and the local system time of the controller.
In the mapp Vision HMI application, this time offset results in image acquisitions becoming slower and slower the further from the last restart of the controller since the calculation of the NetTime for an image acquisition triggered via the HMI application is distorted. The image trigger delay in the mapp Vision HMI application is proportional to the time offset (diagnostics data point NettimeOffset). The rest of the communication between the camera and controller, such as saving and loading vision applications, is not affected.
This time offset can also have an impact on user applications.
It is recommended to let the controller work synchronously to the POWERLINK network. For this purpose, the source of the system timer is configured to the corresponding interface in the controller configuration. For additional information about configuring the timing behavior, see section CPU properties - Timing characteristics in Automation Help.
Fig.: In the controller configuration, configure the "System timer" to the interface used in order to synchronize the local system time of the controller with the interface.