©
National Instruments Corp.
11
NI 9421/9423
The NI 9421/9423 channel registers as ON when the
so
u
rcing-o
u
tp
u
t device applies a voltage or drives a c
u
rrent that is
in the inp
u
t ON range to DI. The channel registers as OFF when the
device applies a voltage or drives a c
u
rrent that is in the inp
u
t OFF
range to DI. If no device is connected to DI, the channel registers
as OFF. Refer to the
Specifications
section for more information
abo
u
t the ON and OFF states.
Each channel has an LED that t
u
rns on and off to indicate the state
of that channel. When a channel LED is lit, the channel is on. When
the LED is dark, the channel is off. The LEDs are disabled when
the chassis is in sleep mode. Refer to the
Sleep Mode
section for
more information abo
u
t sleep mode.
