MCast Control
Properties Methods Events Configuration Settings Errors
The MCast component is used to multicast UDP datagrams to multicast capable hosts in multicast capable subnets. It can act both as a client and a server and communicate with any number of hosts simultaneously, as well as generate and receive broadcast packets.
Syntax
MCast
Remarks
The MCast control is very similar to UDPPort, except for some additional properties that provide support for multicast datagrams. To send datagrams to a multicast group, simply assign the address of the group to RemoteHost. To receive datagrams from one or more groups, assign the group addresses to MulticastGroup one by one (after the control is activated. TimeToLive allows to specify how many subnets a packet should be allowed to receive. ReceiveInterface and SendInterface allow you to select the network interface for multicast operations.
The control is activated/deactivated through the Active property. This property enables or disables sends or receives. The data can be sent in the same way as UDPPort, by calling the Send method with a Text parameter or via the DataToSend property. The destination is specified using the RemoteHost and RemotePort properties. Inbound data is received through the DataIn event.
Property List
The following is the full list of the properties of the control with short descriptions. Click on the links for further details.
| AcceptData | Enables or disables data reception (the DataIn event). |
| Active | Enables or disables sending and receiving data. |
| DataToSend | A string of data to be sent to the remote host. Write-only property. |
| LocalHost | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
| LocalPort | The UDP port in the local host where MCast binds. |
| Loopback | Enables or disables loopback of data sent to the multicast group. |
| MulticastGroup | Multicast group to join or leave. |
| ReceiveInterface | The interface with which to receive multicast packets. If empty, default is used. |
| RemoteHost | The address of the remote host (multicast group). |
| RemotePort | The UDP port in the remote host. |
| SendInterface | The interface from which multicast packets are sent. If empty, default is used. |
| TimeToLive | The maximum number of subnets that a multicast datagram can traverse. |
Method List
The following is the full list of the methods of the control with short descriptions. Click on the links for further details.
| Config | Sets or retrieves a configuration setting . |
| DoEvents | Processes events from the internal message queue. |
| Send | Sends data to the remote host. |
Event List
The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.
| DataIn | Fired when data is received. |
| Error | Information about errors during data delivery. |
| ReadyToSend | Fired when the component is ready to send data. |
Configuration Settings
The following is a list of configuration settings for the control with short descriptions. Click on the links for further details.
| CaptureIPPacketInfo | Used to capture the packet information. |
| DestinationAddress | Used to get the destination address from the packet information. |
| DontFragment | Used to set the Don't Fragment flag of outgoing packets. |
| LocalHost | The name of the local host through which connections are initiated or accepted. |
| LocalPort | The TCP port in the local host where the component binds. |
| MaxPacketSize | The maximum length of the packets that can be received. |
| ShareLocalPort | If set to True, allows more than one instance of the component to be active on the same local port. |
| UseConnection | Determines whether to use a connected socket. |
| QOSDSCPValue | Used to specify an arbitrary QOS/DSCP setting (optional). |
| QOSTrafficType | Used to specify QOS/DSCP settings (optional). |
| UseIPv6 | Whether or not to use IPv6. |
| AbsoluteTimeout | Determines whether timeouts are inactivity timeouts or absolute timeouts. |
| FirewallData | Used to send extra data to the firewall. |
| InBufferSize | The size in bytes of the incoming queue of the socket. |
| OutBufferSize | The size in bytes of the outgoing queue of the socket. |
| CodePage | The system code page used for Unicode to Multibyte translations. |