Usb Connector; Led; Screw Terminal Wiring - Measurement Computing USB-1208LS User Manual

USB-1208LS User's Guide

USB connector

The USB connector is on the right side of the USB-1208LS housing. This connector provides +5V power and
communication. The voltage supplied through the USB connector is system-dependent, and may be less than
5V. No external power supply is required.

LED

The LED on the front of the housing indicates the communication status of the USB-1208LS. It uses up to
5 mA of current and cannot be disabled. The table below defines the function of the LED.
LED state
On – steady green
Blinks continuously
Blinks three times
Blinks at a slow rate

Screw terminal wiring

The screw terminals provide the following connections:
Eight analog inputs (

Two analog outputs (

16 digital I/O connections (

External trigger input (

External event counter input (

Power output (

PC+5 V
Calibration output (

Ground connections (

Use 16 AWG to 30 AWG wire when making connections to the screw terminals. The differential mode pinout
is shown in Figure 3.
LED illumination
Indication
The USB-1208LS is connected to a computer or external USB hub.
Data is being transferred.
Initial communication is established between the USB-1208LS and the computer.
The analog input is configured for external trigger. The LED stops blinking and lights
steady green when the trigger is received.
to )
CH0 IN CH7 IN
to
D/A OUT 0 D/A OUT 1
to
PortA0 Port A7
)
TRIG_IN
)
CTR
)
)
CAL
)
GND
Figure 3. Differential mode pinout
)
, and to )
Port B0 Port B7
9
Functional Details