Using Power From The Pio-12 - Keithley PIO-12 User Manual

Using Power from the PIO-12

Power from the computer supply is available on the main I/O connector of
the PIO-12. In situations where the PIO-12 is used with a dedicated
peripheral (for example, a switch pad) and the cabling and design loads
are fixed, you may find it more appropriate to use the PIO-12 power
outputs. In most other cases, however, you are advised to power external
devices from their own supplies.
In general, you are advised not to use computer power unless you can
safely avoid the following conditions:
Short circuits, overloads, or the application of other external voltages.
All of these conditions may damage the PC system board and result in
costly repairs. The PC power supply is designed to shutdown on a
short circuit, but you should not rely on this characteristic to protect
your system.
A power draw that exceeds the capacity of the computer power
supply and its internal loads (see the technical reference manual for
your computer). Because of computer board connector and trace
width limitations, we recommend that you limit power draw to 1A
from the +5V and +12V supplies (if available). The -12V and -5V
supplies are limited to much lower loads.
After you configure and check your installation and understand the board
power limitations discussed above, you can attach accessories as needed
and wire the external signals to the board. Refer to Section 3 for
instructions.
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