I have made a serial / console (RS-232) connection from my AVN Encoder to my PC, but cannot communicate to it via Hyperterminal. What may be wrong?

There are a couple of possible reasons, the most likely being a bad or improper cable.

AVN200s, and AVN210s connect using a NULL modem cable (D-Sub 9-Pin for RS-232C). A proper cable is shipped with each of these encoders.

All AVN blades (AVN220, AVN420, AVN422, AVN441 and AVN443) use an RJ-45 (8-Pin) to D-SUB 9-Pin for RS-232C, which are the same as CISCO console cables. Each MPP chassis (MPP200 or MPP1700) ships with one of these cables.

Failure to use the proper cable will prevent the serial / console interface from working properly.

Another possible cause is the use of a USB to Serial adapter. While many of these adapters seem to work fine others do not. If you are experiencing strange behavior try a different adapter or use an older PC which has a true serial / COM port.