| 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). |