©
National Instruments Corporation
6-1
6
Digital I/O
Refer to one of the following sections, depending on yo
u
r device:
•
Digital I/O on USB-6210/6211/6215/6218 Devices
—
USB-6210/6211/6215/6218 devices have
u
p to eight lines of digital
inp
u
ts (DI) and
u
p to eight lines of digital o
u
tp
u
t (DO).
•
Digital I/O on USB-6212/6216 Devices
—USB-6212/6216 devices
have
u
p to 32 bidirectional static digital I/O (DIO) lines.
Digital I/O on USB-6210/6211/6215/6218 Devices
USB-6210/6211/6215/6218 devices have
u
p to eight static digital inp
u
t
lines, P0.<0..7>. These lines also can be
u
sed as PFI inp
u
ts.
USB-6210/6211/6215/6218 devices have
u
p to eight static digital o
u
tp
u
t
lines, P1.<0..7>. These lines also can be
u
sed as PFI o
u
tp
u
t. By defa
u
lt the
digital o
u
tp
u
t lines are disabled (high impedance with a 47 k
Ω
p
u
ll-down
resistor) on power
u
p. Software can enable or disable the entire port
(software cannot enable individ
u
al lines). Once the port is enabled, yo
u
can
individ
u
ally config
u
re each line to the following:
•
Set a line to a static 0
•
Set a line to a static 1
•
Export a timing o
u
tp
u
t signal to a line as a PFI pin
The voltage inp
u
t and o
u
tp
u
t levels and the c
u
rrent drive level of the DI and
DO lines are listed in the
NI USB-621x Specifications
. Refer to Chapter 7,
, for more information on PFI inp
u
ts and o
u
tp
u
ts.
Fig
u
re 6-1 shows the circ
u
itry of one DI line and one DO line. The
following sections provide information abo
u
t the vario
u
s parts of the DIO
circ
u
it.
