Integration into the system

The HL7 implementation as we have built it so far consists merely of a library which handles encoding and decoding. However, means have to be provided, by which these functions are controlled. In general, there are many possibilities how to do this. Here we only give a short list of what will be included into the system:

• a batch file interpreter
• a module that handles incoming unsolicited messages, i.e. a program that is invoced by the inter net daemon (inetd(8)) which listens at a certain TCP/IP port for incoming packets
• a module that does the same job on RS-232 lines by listening for incoming messages
• a module that helps connecting a HL7 server via TCP/IP or RS-232

All these modules will use some kind of lower layer protocol as described in the HL7 v2.1 document. While on TCP/IP links the minimal lower layer protocol would be sufficient, the X3.28 based data link protocol will have to be implemented to support RS-232 connections if SLIP or PPP is not used.