Chapter 4 Signal Connections
PCI-4451/4452 User Manual 4-8
©
National Instruments Corporation
Table 4-4.
Digital 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
(ns)
Bias
DGND
DIO —
— — —
—
—
+5 V
DIO 0.15 Ω
Short-circuit
to ground
1A —
—
—
DIO<0..7>
DIO —
Vcc +0.5 13 at
(Vcc
−
0.4)
24 at 0.4
1.1
50 kΩ pu
RESERVED1
DO —
— — —
—
50 kΩ pu
EXTSTROBE*
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI0/TRIG1 (EXT_TRIG)
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI1/TRIG2 (PRETRIG)
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
CONVERT*
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI3/GPCTR1_SOURCE
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI4/GPCTR1_GATE
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
GPCTR1_OUT
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
UPDATE*
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI6/WFTRIG
DIO —
Vcc +0.5 3.5 at
(Vcc -0.4)
5 at 0.4
1.5
50 kΩ pu
PFI7
DI —
Vcc +0.5 — —
—
50 kΩ pu
PFI8/GPCTR0_SOURCE
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
PFI9/GPCTR0_GATE
DIO —
Vcc +0.5 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
GPCTR0_OUT
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
FREQ_OUT
DO —
— 3.5 at
(Vcc
−
0.4)
5 at 0.4
1.5
50 kΩ pu
DIO = Digital Input/Output pu = pullup
DO = Digital Output DI = Digital Input
Note: The tolerance on the 50 kΩ pullup and pulldown resistors is very large. Actual value may range between 17 and 100 kΩ.
User.book Page 8 Tuesday, April 14, 1998 10:20 AM