81001-340-71-R 从控制器变量创建的HMI Tag对于每个HMI客户端都是可见的。如果控制器变量发生变化，则该变化将影响所有HMI客户端的变量;反之，任意一个客户端的变量发生变化，其他客户端及控制器变量也会跟着变化。

An eHMI application can be created in PLCnext Engineer to visualize, monitor, and operate programs running on the controller.

The 81001-340-71-R application consists of several HMI pages, each filled with multiple standard HMI Objects or custom HMI Symbols. The eHMI application data is automatically stored as part of the project and written to the project image of the controller when executing the "write and start project" command. Through the web server on the controller, eHMI applications can be run in a standard web browser, and then monitor and control the processes running on the controller.

HMI Tag can be considered as an internal variable of HMI, and different levels of 81001-340-71-R have different attributes. Making full use of tags can achieve some complex interface effects.

The HMI Tag created from the controller variable 81001-340-71-R is visible to every HMI client. If there is a change in the controller variable, it will affect the variables of all HMI clients; On the contrary, if the variable of any client changes, the variables of other clients and controllers will also change accordingly.