ICS as HL7 Server

[damos 0]

Hi i am Testing ICS as HL7 Server on AvailDataAvailable  i have wrote

 

procedure TcpSrvForm.ClientDataAvailable( Sender : TObject;  Error  : Word);
Var
  Client: TWSocketClient;
  Buffer: AnsiString;
  ReceivedData: string;
  AckMsg: string;
  Len: Integer;
begin
  if Error <> 0 then
  begin
    Display('Socket Error: ', Error);
    Exit;
  end;

    Client := Sender as TWSocketClient;

  Len := Client.ReadCount;
  if Len <= 0 then Exit;

  SetLength(Buffer, Len);
  Client.Receive(@Buffer[1], Len);

  // Convert buffer to string and trim unnecessary spaces
  ReceivedData := Trim(String(Buffer));

  // Ensure message ends with <CR>
  if (not ReceivedData.IsEmpty)  and (Strutils.RightStr(ReceivedData,1)=#13)

then
  begin
    Display('Received HL7 Message: '+ReceivedData);

    // Create HL7 Acknowledgment (ACK)
    AckMsg := 'MSH|^~\&|RECEIVER|SENDER|ACK||' + FormatDateTime('YYYYMMDDHHNNSS', Now) +
              '||ACK|' + IntToStr(Random(1000000)) + '|P|2.3' + #13 +
              'MSA|AA|' + 'MSG12345' + #13;

    // Send ACK back to client
    Client.SendStr(#11+AckMsg+#28+#13);
     Display('Sent ACK: '+AckMsg);

  end
  else
  begin

    Display('Incomplete HL7 message received (waiting for <CR>)');
  end;
  end;

Each HL7 block has the following format

 

#11+HL7Block+#28+#13  or VT +HL7Message +FS+CR

Each HL7Block consist 

Messages  ending with CR

Example

VT

MSH|^~\&|OR-CO|MIRTH|LISSYSTEM||20191126132820||ADT^A04^ADT_A04|2653973|P|2.4+CR
EVN|A01||||OR-CO|20191126132400+CR
PID|||22522527||CCCCCCCCCC^VVVVVVVV^KKKKKKKK||19581003000000|M|||ΠΕΤΡΟΥ ΡΑΛΛΗ 3^^ΑΘΗΝΑ^^15121||2106127519||||||27014802733+CR
NK1|1|^ΜΑΡΙΑ|MTH+CR
PV1||E|392^102106001^0^392||||1068^SSSSSS^DDDDDD||||||||||||1-2611222|||||||||||||||||||||||||20191126132400+CR
DG1|||D64.9^LLLLLLLLLLLL+CR
IN1|||551OOOOOOOOOOOOOOO|||||||||||||||||||||||||||||||||||||||||||||11456652+CR

VT+CR

 

 

 

 This is Working only When Client is disconnected  never reach data from client

 Each message Block from Client has to be Acknowledgement by HL7 ACK message

 I have tested with LineEnd=#13 and LineEnd=#28#13

[Angus Robertson 592]

Never heard of HL7, but it looks like a simple ASCII protocol, one line at a time. 

 

I'd suggest you use the TIcsIpStrmLog component in TCP Server mode which has an onRecvEvent that returns a simple line at a time, you can define the line end in various ways. 

 

The main sample is  OverbyteIcsIpStmLogTst,dpr that sends and receives lines of data, including to itself.  ICS V9,4 adds a new component OverbyteIcsAppMonSrv.pas that handles a text protocol very similar to your example with | as field separators, communicating between different ICS applications, with a new sample IcsAppMon.dpr use the server component to collect information from multiple clients and return information those clients. 

 

Angus

 

[KenR 29]

I use a TWSocket to listen for HL7 transmissions. It works perfectly.

 

Ken

[FPiette 387]

I have used TWSocket for hospital application (HL7 V2.3) and never had any issue.

You should turn line mode on and use CR as line end.

The as it is ASCII, use ReceiveStr to get the lines one at a time into a string.

[damos 0]

I follow the example and Use

 

procedure TForm6.WSocketServer1DataAvailable(Sender: TObject; ErrCode: Word);

Var
  ReceivedData: string;
  AckMsg: string;

begin

  if ErrCode <> 0 then Exit;

   with Sender as TWSocket do begin
     ReceivedData := ReceiveStr;
     ReceivedData := LeftStr(ReceivedData,Length(ReceivedData)-Length(LineEnd));  // remove EndOfLine
     DisplayMemo.Lines.Add('Line: '+ IntToStr(Length(ReceivedData)) +' '+ReceivedData);
   end;

     AckMsg := 'MSH|^~\&|RECEIVER|SENDER|ACK||' + FormatDateTime('YYYYMMDDHHNNSS', Now) +
              '||ACK|' + IntToStr(Random(1000000)) + '|P|2.3' + #13 +
              'MSA|AA|' + 'MSG12345' + #13;

end;

 

Never get the message from Client can you give a simple example that line ends with FS+CR  (#28#13)  With Indy works Fine

[Angus Robertson 592]

Of course TWSocket can be used for HL7, but using TIcsIpStrmLog requires a lot less code.  OverbyteIcsAppMonSrv.pas even parses the | delimited fields.  

 

Angus

 

[FPiette 387]

1 hour ago, damos said:

Never get the message from Client can you give a simple example that line ends with FS+CR  (#28#13)

In HL7, end of segment is single CR (#13). Set TWSocket LineEnd to single #13.

[damos 0]

I have to disagree with you General format on common versions of HL7  2.3....2.7 are standard   VT+HL7Block+FS+CR  , each  HL7Block consist of HL7 records according the version each line end with CR

\x0B

MSH|^~\&|... 

PID|... PV1|... 

\x1C\x0D

i have to read all the block that is ending with FS+CR (MIRTH OPERATION) and answer with ACk or NAK the HL7 message that is the flow Control

 

I have also try with LineEnd=#13

i have attach simple project and simple Flow from HL7 client

 

Socket.rar

[Angus Robertson 592]

You would be better to avoid using LineMode if the lines are 'unusual', always read all received data, buffer it, and check for end of line/row/packet yourself, which can be multiple methods. 

 

That is what the TIcsIpStrmLog  component does, but you may need to copy the code to add more flexibility.

 

Angus