Emulex MD21/S2, Technical Manual

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MD21 Controller Installation
C A U T I O N
If diode leads are reversed so that the anode of
the diode is in the wrong hole, the system will not
function properly (the cathode end is usually
identified by a white line or other unique marking
on the diode).
If there are multiple controllers attached to the
SCSI bus and power is removed from the MD21
Controller that is configured to supply the
terminator power, the other controllers will not
function correctly. Under these conditions, the
host should supply the power.
5.3.3 SCSI BUS TERMINATION
The MD21 Controller can be configured to terminate the SCSI bus by
inserting one 220/330-ohm resistor pack in the sockets located at
U22 and U35 on MD21. The resistor packs are available in the Emulex
SCSI terminators kit, P/N MD0113002. A SCSI system configuration
should contain only two devices that terminate the SCSI bus.
Usually these devices are a host adapter and one peripheral device
controller (such as the MD21 Controller). Termination should be
installed only on the controller that is physically last on the
SCSI bus.
5.4 MD21 CONTROLLER INSTALLATION
This subsection describes a sample procedure for installing the
MD21 Controller in the disk drive chassis. To install the MD21,
see Figures 5-6 and 5-7 and use the following procedure:
NOTE
The installation instructions and figures in this
subsection assume the use of an Emulex mounting
bracket to install the MD21 on top of the ESDI
disk drive. It is necessary to use some kind of
intermediary device so that the controller does
not sit directly on the disk drive. One mounting
bracket for use with the MD21 is available in
Emulex kit number MD0113003.
5-8 Installation