Increasing Current Drive On Usb-6210/6211/6215/6218 Devices; Connecting Digital I/O Signals On Usb-6210/6211/6215/6218 Devices - National Instruments USB-621 Series User Manual

Increasing Current Drive on USB-6210/6211/6215/6218 Devices

Connecting Digital I/O Signals on USB-6210/6211/6215/6218 Devices

LED
+5 V
When using a
USB-6215/6218,
you must connect
D GND and/or AI GND
to the local ground
on your system.
Exceeding the maximum input voltage ratings, which are listed in the
Caution
NI USB-621x Specifications, can damage the DAQ device and the computer. NI is not
liable for any damage resulting from such signal connections.
© National Instruments Corporation
The total internal current limit for digital outputs and power drawn from the
+5 V terminals is 50 mA. You can increase this internal current limit by
supplying an external +5 V supply. Refer to the
section of Chapter 3,
The DI and DO signals, P0.<0..7> and P1.<0..7> are referenced to D GND.
Digital input applications include receiving TTL signals and sensing
external device states, such as the state of the switch shown in the figure.
Digital output applications include sending TTL signals and driving
external devices, such as the LED shown in Figure 6-2.
+5 V
TTL Signal
Switch
I/O Connector
Figure 6-2. USB-6210/6211/6215/6218 Digital I/O Connections
Connector and LED
P1.<0..3>
P0.<0..3>
D GND
USB-6210/6211/6215/6218 Device
6-3
Chapter 6
+5 V Power as an Input
Information.
Isolation
Barrier
(USB-6215
and USB-6218
devices only)
Digital
Isolators
NI USB-621x User Manual
Digital I/O