If the server (refractometer) does not recognize the request or cannot fulfill it, it responds with an error message. The error message has the following keys:
- *Error: integer, error code 0x00000000: Unknown request
- *Error: integer, error code 0x00000001: Invalid request (request recognized, invalid request data)
- *Error: integer, error code 0x00000002: Invalid sensor number
- ErrorMsg: string, error details
There may also be error-dependent extra keys. Other error codes may be returned. 0x00000003 is handled as an unknown request. Codes with higher numbers refer to internal errors; contact Vaisala for more information.