1. Make sure the controller ID on VK2100 and VK236 are set to the same ID number

2. If you have more than one expanders, please ensure the device IDs are not duplicated but unique

3. Connect the expanders and VK2100 to the same network range (fragment)

4. Turn on VK2100 and expanders, wait till all the devices are ready and check the indication light on expanders. The Link indication light must show green solid

For full details, please see the video below.