LSI 8751D 2.2.4 SCSI Bus Termination

2.2.4 SCSI Bus Termination

The devices making up the SCSI bus are connected serially (chained together) with SCSI cables. The ﬁrst and last physical SCSI devices connected on the ends of the SCSI bus must have a set of resistors called terminators. All other SCSI devices on the bus must have their terminators removed or disabled. Remember that the LSI8751D is also on the SCSI bus; if you position the host adapter at the end of the SCSI bus, you must place the supplied HVD terminator on the unused connector (J2 or J3).

The peripheral device terminators are usually set with jumpers, resistor modules, or a switch on the peripheral. Refer to the peripheral manufacturer’s instructions and to the user’s manual for your computer for information on how to identify the terminator setting of each device and how to change it.

The LSI8751D automatically covers SCSI bus termination for three different bus conﬁgurations, depending on the use of the connectors J2 and J3 on the LSI8751D (see Figure 2.1). The three bus conﬁgurations are

•only for internal SCSI connections to connector J2

•only for external SCSI connections to connector J3

•for SCSI connections to both J2 and J3 connectors

Termination on the LSI8751D for these three different bus conﬁgurations is discussed in the following sections.

2-14	Installing the LSI8751D

Contents

USER’S GUIDE Electromagnetic Compatibility Notices Page Page Preface Related Publications Revision Record Contents Page Figures Page Tables Page Describing the LSI8751D 1.1General Description 1.2 Features 1.2.1 PCI Interface 1.2.2SCSI Interface 1.2.3Board Characteristics 1.2.4Ultra SCSI Page Installing the LSI8751D 2.1Quick Installation Procedure 2.2 Detailed Installation Procedure 2.2.1 Before You Start 2.2.2 Inserting the Host Adapter Figure 2.2 Inserting the Host Adapter 2.2.3 Connecting the SCSI Peripherals Figure 2.3 SCSI Cables 2.2.3.1 Making Internal SCSI Bus Connections Figure 2.4 Internal SCSI Ribbon Cable to Host Adapter Connection Figure 2.5 Internal SCSI Ribbon Cable to Internal SCSI Device Connection Figure 2.6 Connecting Additional Internal SCSI Devices Figure 2.7 Multiple Internal SCSI Devices Chained Together Figure 2.8 SCSI LED Connector 2.2.3.2 Making External SCSI Bus Connections Figure 2.9 External Cable to Host Adapter Figure 2.10 External Cable to External SCSI Device Figure 2.11 Multiple External SCSI Devices Chained Together 2.2.4 SCSI Bus Termination 2.2.4.1 Internal SCSI Connections Figure 2.12 Internal SCSI Device Termination 2.2.4.2 External SCSI Connections Figure 2.13 External SCSI Device Termination 2.2.4.3 Internal and External SCSI Connections Figure 2.14 Internal and External SCSI Device Termination 2.2.5 Setting SCSI IDs Table SCSI ID Record 2.3 Completing the Installation Page Technical Speciﬁcations 3.1Physical Environment 3.1.1 Physical Characteristics 3.1.2 Electrical Characteristics 3.1.3 Thermal, Atmospheric Characteristics 3.1.4Electromagnetic Compliance 3.1.5 Safety Characteristics 3.2 Operational Environment 3.2.1 The PCI Interface Table 3.2 PCI Connector JI (Top) 3.2.2 The SCSI Interface 3.2.3 The LED Interface Appendix A Glossary of Terms and Abbreviations Conﬁguration CPU DMA DMA Bus Master Fast SCSI FCC File Firmware Hard Disk LVD SCSI Mainboard Main Memory Mbyte Motherboard Peripheral Devices Pin-1Orientation PIO Port Address Port Number SCSI Bus SCSI Device SCSI ID SDMS Single-Ended VCCI VDE Virtual Memory Wide SCSI Wide Ultra SCSI Page Index Page Customer Feedback Reader’s Comments http://www.lsilogic.com/contacts/na_salesofﬁces.html Headquarters