Signal Connections
Chapter 3
DAQCard-500 User Manual
3-2
© National Instruments Corporation
Signal Connection Descriptions
Pin
Signal Name
Description
1
AIGND
Analog Input Ground—This signal is the common ground tie-in point
for all analog signals.
2–9
ACH<0..7>
Analog Input Channels 0 through 7—These signals are the single-ended
analog input signals.
10
+5 V
+5 Volts—This pin pr5 VDC. The +5 V supply is fused at 1 A,
which is the maximum current available.
11
EXTCONV*
External Convert Signal—This input signal externally initiates an A/D
conversion.
12–15
DIN<0..3>
Digital Input Data Lines—These signals are TTL-compatible, digital
input lines. DIN3 is the MSB; DIN0 is the LSB
16–19
DOUT<0..3>
Digital Output Data Lines—These signals are TTL-compatible digital
output lines. DOUT3 is the MSB; DOUT0 is the LSB.
20
1 MHz
1 MHz Square Wave Output of Oscillator—This signal is a 1 MHz
square wave for use with the internal counter or external timing needs.
21, 27
DGND
Digital Ground—This is the common ground tie-in point for all digital
signals.
22
CLK1
Clock Input of Counter 1—This signal is the clock input of counter 1.
23
OUT1
Output of Counter 1—This signal outputs the programmed waveform of
counter 1.
24
GATE2
Gate Input of Counter 2—This signal controls the starting, interruption,
and restarting of counter 2.
25
CLK2
Clock Input of Counter 2—This signal is the clock input of counter 2.
26
OUT2
Output of Counter 2—This signal outputs the programmed waveform of
counter 2.
28–30
NC
Not Connected—These signals are not connected.
Note: An asterisk (*) indicates that the signal is active low.
The connector pins are grouped into analog input signal pins, digital I/O signal pins, and timing
I/O signal pins. Signal connection guidelines for each of these groups are included in the
following pages.
Analog Input Signal Connections
Pins 1 through 9 are analog input signal pins for the ADC. Pin 1, AIGND, is an analog common
signal. You can use these pins for a general analog power ground tie to the DAQCard-500. Pins
2 through 9 are the ACH<0..7> signal pins. These pins are tied to the analog input channels of
the DAQCard-500 through 4.7 k series resistors. These resistors limit the input current
