Hi guys, i have OC200 and i wish to know whether am i able to adopt omada devices from another network?

Site A has
OC200

Site B has
ER605
TPLINK EAP

What ive tried is resetting both devices at site B to factory default. Follow by inputting the DDNS under controller inform URL in ER605 
For TPLINK EAP i have tried adopting it as standalone. login to the management interface and input the controller inform URL  

But my OC200 unable to find any device thats pending.

I tried nslookup at SITE B, i did manage to be able to see the OC200. 

what am i suppose to do?

Thankyou in advance