Areca ARC-1880 Series User Manual page 27

HARDWARE INSTALLATION
Step 7. Install the LED Cable (option)
The preferred I/O connector for server backplanes is the inter-
nal SFF-8087 connector. This connector has eight signal pins to
support four SAS/SATA drives and six pins for the SGPIO (Serial
General Purpose Input/Output) side-band signals. The SGPIO bus
is used for efficient LED management and for sensing drive Locate
status. See SFF 8485 for the specification of the SGPIO bus. For
backplane without SGPIO supporting, Please refer to Section 2.4
LED cables for fault/activity LED cable installation.
LED Management: The backplane may contain LEDs to indicate
drive status. Light from the LEDs could be transmitted to the out-
side of the server by using light pipes mounted on the SAS drive
tray. A small microcontroller on the backplane, connected via the
SGPIO bus to a 6Gb/s SAS RAID controller, could control the LEDs.
Activity: blinking 5 times/second and Fault: solid illuminated
Drive Locate Circuitry: The location of a drive may be detected by
sensing the voltage level of one of the pre-charge pins before and
after a drive is installed.
The following signals define the SGPIO assignments for the Min
SAS 4i internal connector (SFF-8087) in the 6Gb/s SAS RAID con-
troller.
PIN
SideBand0 SClock (Clock signal)
SideBand2
SideBand4 SDataOut (Serial data
SideBand6
The SFF-8087 to 4 SATA with sideband cable which follows
SFF-8448 specification. The SFF-8448 sideband signals cable
is reserved for the backplane with header on it.The following
signal defines the sideband connector which can work with Areca
sideband cable on its SFF-8087 to 4 SATA cable.
Description
Ground
output bit stream)
Reserved
PIN
SideBand1 SLoad (Last clock of a bit
SideBand3
SideBand5 SDataIn (Serial data input bit
SideBand7
Description
stream)
Ground
stream)
Reserved
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