1.1 This specification describes the electronic transmission of digital information between clinical laboratory instruments and computer systems. The clinical laboratory instruments under consideration are those that measure one or more parameters from one or more patient samples. Often they will be automated instruments that measure many parameters from many patient samples. The computer systems considered here are those that are configured to accept instrument results for further processing, storage, reporting, or manipulation. This instrument output may include patient results, quality control results, and other related information. Typically, the computer system will be a Clinical Laboratory Information Management System (CLIMS).
1.2 The terminology of the Organization for International Standards (ISO) Reference Model for Open Systems Interconnection (OSI) is generally followed in describing the communications protocol and services. The electrical and mechanical connection between instrument and computer is described in the Physical Layer section. The methods for establishing communication, error detection, error recovery, and sending and receiving of messages are described in the Data Link Layer section. The data link layer interacts with higher layers in terms of sends and receives "messages," handles data link connection and release requests, and reports the data link status.
1.3 This specification addresses the low level protocol used for both serial binary data exchange and TCP/IP data exchange. For message content in the interface between clinical instruments and computer systems, reference Specification E 1394. Topics are found in the following sections:
For Serial Binary Data Exchange SectionPhysical Layer5Overview 5.1Electrical Characteristics5.2Signal Levels5.2.1Character Structure 5.2.2Speed5.2.3Interface Connections5.2.4Mechanical Characteristics5.3 Connector5.3.1 Cable 5.3.2Data Link Layer5Overview6.1 Establishment Phase (Link Connection) 6.2Contention6.2.1 Transfer Phase6.3 Frames6.3.1 Frame Number6.3.2Checksum 6.3.3Acknowledgments6.3.4 Receiver Interrupts6.3.5 Termination Phase (Link Release) 6.4Error Recovery6.5 Defective Frames6.5.1 Timeouts 6.5.2Restricted Message Characters6.6 For TCP/IP Data ExchangePhysical Layer7Overview7.1Electrical Characteristics7.2Signal Levels7.2.1Character Structure7.2.2Speed7.2.3Interface Connections7.2.4Mechanical Characteristics7.3Connector7.3.1Cable7.3.2Data Link Layer8Overview8.1Establishment Phase (Link Connection)8.2Contention8.2.1Transfer Phase8.3Frames8.3.1Frame Number8.3.2Checksum8.3.3Acknowledgments8.3.4Receiver Interrupts8.3.5Termination Phase (Link Release)8.4Error Recovery8.5Defective Frames8.5.1Timeouts8.5.2Restricted Message Characters8.6