Check the results of the Comms Analysis by using the network test utility. If the network utility test returns any characters that are not numeric (ie only 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are permitted) then you will need to :-

1. Check that the network is correctly earthed
2. The controller(s) are correctly functioning Test each failing door controller locally to the protocol convertor

• If the controller functions correctly when connected locally you can suspect faulty network cable
• If the controller still delivers data errors, whilst other doo controllers do not, then you should suspect the door controller