边缘计算网关自带1路开关量输入（DI），可以实时获取开关量输入的状态。

1.准备工作

对于开关量输入的测试相当于比较简单，当前采用的是24V电容式接近开关；有接近时值为1，无接近时值为0。

用了一个220V转24V的电源适配器。

下面为接近开关的链接

下面为电源的链接

2、进入Node-red实例中，进行节点配置

2-1、节点接线图

2-2、节点配置如下：

2-3、接近和未靠近测试效果图

未靠近，传感器（接近开关）

靠近，传感器（接近开关）

3、Node-red流程完整代码

[{"id":"e7facfe317ebb380","type":"di","z":"eb68d021136355ea","name":"","index":"1","interval":true,"intervalValue":1000,"x":250,"y":220,"wires":[["5928d218f8ec86c2"]]},{"id":"5928d218f8ec86c2","type":"debug","z":"eb68d021136355ea","name":"debug 7","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":440,"y":220,"wires":[]},{"id":"82740cb9b57a1bb2","type":"global-config","env":[],"modules":{"node-red-AIoTedge-A300":"1.0.0"}}]