Great. Thank you for that suggestion.
According to a gentleman at tech support, this device is so old it's not even mentioned on company webpage. But he had a personal copy of PDF that he is going to email it to me.
I actually found this on some website (other than the official one). But its one of those with view only and with fake "download" link. I didn't trust them what it would actually "download." So trusted source like this was wonderful.
2 minutes later, the official manual has arrived in my in box.