Fangrui Product Details 1. Gp4 Supports Sms Control, App Control, Ai/di With Remote Linkage Actions. It Supports 4-way Relay Output (10a Nonc), 4-channel Digital Input (dry-contact), And 4-channel Current Acquisition (4-20ma). It Operates With A Wide Input Voltage Range Of 9v To 24v. It Is Suitable For Access Control, Building Automation, And Automatic Industrial Systems. 2. Gp4-wlte Is A 4-channel Di/do/ai 4g Remote Controller. The Controller Includes 4 Channels Of Digital Input (di), Digital Output (do), And Analog Quantity Input (ai). The Di Supports Dry Contact Detection; Do Provides Relay Output With A Control Ability Of 10a At 250vac Or 15a At 30vdc. The 4 Channels Of Ai Input Support 4-20ma Current Input, With An Accuracy Of 12 Bits. Gp4 Supports 2 Control Methods: App And Sms. 3. Gp4-wlte Is An Io Controller That Utilizes The 4g Network For Control. The Primary Control Method Is Through The Wlte Control App, Which Can Be Easily Found In The App Market. This App Allows For Convenient Parameter Configuration And Linking T