Chapter 4 Signal Connections

PCI-4451/4452 User Manual 4-8

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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 ΩShort-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