Appendix A
Connecting I/O Signals
©
National Instruments Corporation
A-5
R Series Intelligent DAQ User Manual
Caution
Connections that exceed any of the maximum ratings of input or output signals
on the NI 78
xx
R can damage the NI 78
xx
R and the computer. Maximum input ratings for
each signal are in the
Protection
column of Table A-2. NI is
not
liable for any damage
resulting from such signal connections
Table A-2.
NI 78
xx
R I/O Signal Summary
Signal Name
Signal
Type and
Direction
Impedance
Input/
Output
Protection
(Volts)
On/Off
Source
(mA at V)
Sink
(mA at V)
Rise Time
Bias
+5V
DO
—
—
—
—
—
—
Analog Signals (NI 783
x
R/784
x
R/785
x
R Only)
AI<0..7>+
AI
10 G
Ω
in
parallel with
100 pF
42/35
—
—
—
±2 nA
AI<0..7>–
AI
10 G
Ω
in
parallel with
100 pF
42/35
—
—
—
±2 nA
AIGND
AO
—
—
—
—
—
—
AISENSE
AI
10 G
Ω
in
parallel with
100 pF
42/35
—
—
—
±2 nA
AO<0..7>
AO
1.25
Ω
Short
circuit to
ground
2.5 at 10
2.5 at –10
10 V/
µ
s
—
AOGND
AO
—
—
—
—
—
—
Digital Signals (All NI 78
xx
R Devices)
—
—
—
—
DIO<0..39>
Connector<0..3>
(NI 781
x
R)
DIO<0..15>
Connector 0
(NI 783
x
R,
NI 784
x
R, and
NI 785
x
R)
DIO<0..39>
Connector <1..2>
(NI 783
x
R,
NI 784
x
R, and
NI 785
x
R)
DIO
—
–0.5 to +7.0
(NI 783
x
R)
–20 to 20
(NI 784
x
R/
NI 785
x
R)
4.0 at 2.4
4.0 at 0.4
—
—
AI = Analog Input
AO = Analog Output
DIO = Digital Input/Output
DO = Digital Output
Summary of Contents for NI 781 R Series
Page 1: ...PXI 7842...
