MLLPServer Bean

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The MLLPServer component implements the server side of the Minimal Lower Layer Protocol.

Syntax

InEDI.Mllpserver

Remarks

The MLLPServer bean is used to exchange HL7 data with one or more connected MLLP clients.

Setting up MLLPServer to Listen for Client Connections

The first step in using the MLLPServer bean is to configure it to listen for MLLP client connections. Start by setting the LocalPort property to the desired listening port. For multi-homed devices, also set the LocalHost property to the address of the network interface the MLLPServer bean should listen on.

Next, optionally enable TLS/SSL with the SSLEnabled and SSLCert properties (MLLPServer supports client authentication with the SSLAuthenticateClients property).

Finally, set the Listening property to True to begin listening for client connections.

Connecting Example

mllpServer.LocalHost = "localhost";
mllpServer.LocalPort = 7777;

// The following two lines are only necessary if using TLS/SSL.
mllpServer.SSLEnabled = true;
mllpServer.SSLCert = new Certificate(CertStoreTypes.cstPFXFile, "..\\path\\to\\cert.pfx", "password", "*");

mllpServer.Listening = true;

At this point the ConnectionRequest event will fire anytime a client wishes to connect (connection requests are accepted by default), and the Connected event will fire each time a client successfully connects.

While clients are connected, the server may interact with them by using their ConnectionId to retrieve an MLLPConnection object from the Connections map property.

Receiving Data

The MLLPServer bean will automatically receive HL7 data sent from each client, and will automatically send acknowledgements back.

When the MLLPServer bean is receiving data, immediately before data transfer begins the StartTransfer event fires. During data transfer, one or more Transfer events will fire. When data transfer is complete, the EndTransfer event fires. Any errors during data delivery will cause the Error event to fire.

Immediately before the server acknowledgement is sent the AckOut event fires. The Accept parameter of this event is used to determine the type of acknowledgement (ACK or NAK) to send back to the client.

HL7 data received by the MLLPServer bean will be stored in one of the following ways:

• If an output stream has been specified for the connection using the OutputStream field, the data is written to that stream.
• Otherwise, if an output file path has been set to the OutputFilename field, the data is written to that file.
• Otherwise, the data is stored in the OutputData field.

Sending Data

The MLLPServer bean may also send data to MLLP clients. First, specify the data to send by doing one of the following:

• Set the InputStream field to a stream with HL7 data.
• Set the InputFilename field to the path of a file with HL7 data.
• Set the HL7 data directly to the InputData field.

Once the data has been specified, simply call the Send method with the appropriate connection Id to send the HL7 data to the associated client. Once the client has received the data, it will respond with an acknowledgement, causing the bean's AckIn event to fire.

Sending Data Example

mllpServer.Connections[connectionId].InputData = "HL7Data";
mllpServer.Send(connectionId);