These are possible error code for callback functions.
| Enumerator |
|---|
| EI_API_eERR_CB_NO_ERROR | |
| EI_API_eERR_CB_VAL_TOO_HIGH | |
| EI_API_eERR_CB_VAL_TOO_LOW | |
| EI_API_eERR_CB_INVALID_VALUE | |
| EI_API_eERR_CB_NOT_ENOUGH_DATA | |
| EI_API_eERR_CB_TOO_MUCH_DATA | |
| EI_API_eERR_CB_CONFLICT_STATE | |