| ftvspcErrorOk | 0 | The operation completed successfully. |
|---|---|---|
| ftvspcErrorFailed | 1 | The operation has not been completed. |
| ftvspcErrorInvalidParameter | 2 | Invalid parameter. |
| ftvspcErrorAlreadyInitialized | 3 | Already initialized. |
| ftvspcErrorInsufficientBuffer | 4 | Insufficient buffer size. |
| ftvspcErrorInvalidLicense | 5 | Invalid license. |
| ftvspcErrorIncompatibleVersions | 6 | Incompatible versions of service and DLL API. |
| ftvspcErrorPortAlreadyExists | 100 | This port already exists. |
| ftvspcErrorNoSuchPort | 101 | There is no such port. |
| ftvspcErrorNoMoreItems | 102 | There is no item (possible reason: index is too high). |
| ftvspcErrorPortAttached | 200 | This port is already attached. |
| ftvspcErrorPortInUse | 201 | This port is opened by serial application. |
| ftvspcErrorMarkedForDeletion | 202 | This port is marked for deletion. |
| ftvspcErrorOperationUnsupported | 1001 | Operation unsupported (only for .Net and ActiveX control). |