Chapter 4
Signal Connections
Getting Started with Your PCI/PXI-6810 SDA
4-4
©
National Instruments Corporation
Using External Power with the DIO Signals
The 6810 device normally supplies 5 V power to its eight DIO signals.
However, there may be cases where it is useful to operate these signals
at other voltages. You can use the EXT power pin to supply a voltage
between 2.0 V and 3.6 V to the DIO transceivers, and thereby change
their output high and output low voltages. This feature is especially
useful in testing portable equipment, such as devices that typically
operate at low voltages. To use this feature, change the switch on the
6810. Figures 2-1 and 2-2 in Chapter 2, Configuration and
Installation, depict the location of this switch on each 6810 device, and
the correct position of the switch for the onboard 5 V supply or the
external power source.
4
GPC
General-Purpose Clock—The 6810 either transmits or
receives a clock signal depending on software
configuration. The signal levels for the clock are the
same as the general-purpose channel signals.
2–3
GPCH<0..1>
General-Purpose Serial Channel—Generates or receives
serial data signals between ±10 V depending on whether
the appropriate channel on the 6810 is configured for
output or input.
38, 40
DOE_CH<0..1>
Drive Output Enable—This 5 V TTL active low signal
asserts whenever the 6810 activates the signal drive
circuitry data on the corresponding GPCH<1..0> signal. It
provides the system integrator a means to control any
external hardware that may be connected to the GPCH
signals.
1
+5 V
+5 Volts—Power provided by the 6810 device.
Table 4-1.
I/O Connector Signals (Continued)
Pin
Signal Name
Description
