Hi Kriest
The 'usual' OP7 error numbers are listed in the manual, but guess what? There's no 044! All OP7 error codes have 3 digits, and the first digit indicates the category of error. In this case 0 = driver error. The nearest '0' errors I can find are '041' and '045'. These represent - possible fault in transmission link (e.g. cable) or incorrect parameters set (baud rate etc); and no connection with CPU established.
Has this connection ever worked? If so, what has changed since the last time it did?
Regards
Ken