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National Instruments Corporation
13
NI 9157/9159 Operating Instructions and Specifications
Caution
The C terminals are internally connected to the body of the chassis to prevent a
faulty ground connection from causing the chassis ground to float. If you reverse the input
voltage, the positive input voltage is connected directly to the chassis. The chassis has
built-in reversed-voltage protection, but reversed voltage can damage connected
peripherals if the chassis ground is not reliably connected to earth ground.
Caution
Do not tighten or loosen the terminal screws on the power connector while the
power connector is plugged into the chassis or while the power supply is on.
Connecting One or More NI 9157/9159 Chassis
to the MXI-Express Host System
Complete the following steps to connect one or more NI 9157/9159 chassis
to a MXI-Express host system.
1.
Make sure the MXI-Express host system is set up and configured as
described in the
MXI-Express (x1) for PXI Express User Manual
.
2.
If the MXI-Express host system is powered up, power it down.
3.
If the NI 9157/9159 is powered up, power it down.
4.
Use a MXI-Express cable to connect the MXI-Express host system to
the Upstream port of the first NI 9157/9159 in the chain.
5.
Use a MXI-Express cable to connect the Downstream port of the first
NI 9157/9159 to the Upstream port of the next NI 9157/9159 in the
chain.
Note
The maximum number of NI 9157/9159 chassis in a chain depends on the system
configuration. For example, a PXI system with an NI PXI-8196 controller can support four
chassis per chain. Different types of systems may support more or fewer chassis per chain.
For more information about how different system configurations can affect the maximum
number of chassis in a chain, go to
ni.com/info
and enter the Info Code
915xchain
.
6.
Power up all of the connected NI 9157/9159 chassis.
7.
Power up the MXI-Express host system.
Caution
All connected NI 9157/9159 chassis must have power connected before the host
system is powered up. The BIOS and OS of the host system must detect all bus segments
on the chassis side in order to configure the PCI hierarchy. Powering connected chassis up
or down while the host system is running can cause system hangs and data corruption.
Caution
Do
not
remove MXI-Express cables while power is connected. Doing so can
cause hangs or application errors. If a cable becomes unplugged, plug it back in and reboot.
