8-Slot NI PXIe-1082 Backplane Installation Guide
14
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Power
Refer to the
PXI Express Hardware Specification
for power requirements
and to the specifications of the chosen power supply to determine the
minimum load required.
Connector J37
Connector J37 is the NI PXIe-1082 backplane power supply connector.
Figure 11 shows the J37 location. Refer to Table 2 for the pin descriptions.
Connector J37 consists of eight #12 pins (1 to 4 and 26 to 29) for power.
There also are 21 #20 pins (5 to 25) for mixed power and signaling. Table 2
also indicates which pins must be connected for basic backplane operation.
Refer to the CompactPCI Express specification for details regarding
PS_ON# and PS_OK.
Caution
Do not use the voltage sense pins (22, 23, and 25) to power the board. These pins
are connected by thin trace to the backplane center and are for voltage sensing only.
Providing current through these pins may damage the backplane. If your power supply has
voltage sensing, use these pins; otherwise, leave them unconnected. Pins with “power
plane” in the description are connected to the backplane’s internal power planes and are
suitable for carrying current.
Note
Tyco Electronics manufactures the J37 mating connector, which you can order with
part number 298-08-01100.
Note
The connector SMBus pins are connected to the backplane SMBus, which the
CompactPCI Express specification defines. (The specification also defines uses and
addressing.) Improper use of the SMBus could result in system controller malfunctions.
There are three SMBus slave devices on the NI PXIe-1082 backplane. The
Backplane Descriptor EEPROM is at slave address A4
H
as defined by the
CompactPCI Express specification, and the backplane clocking CPLD is at
slave address 5A
H
. There is a temperature monitoring device at slave
address 5C
H
. If you must connect an SMBus slave device to the J37 SMBus
pins, use slave address 58
H
.
