Strain Relief Slot; Usb Connector; Led; Connecting Wires To The Spring Terminals - Measurement Computing USB-2404-UI User Manual

USB-2404-UI User's Guide

Connect the positive signal of the signal source to the positive input signal terminal (

Connect the negative signal of the signal source to the negative input signal terminal (

Connect to the excitation terminals (
The spring terminal assignments for each input mode are listed in the following table.
Voltage
Terminal
TC
3 —
4 HI
5 LO
6 —
Refer to "USB-2404-UI circuitry" on page 13 for information about connections in each mode.

Strain relief slot

Use the strain relief slot to keep the USB cable from disconnecting from the device inadvertently. Feed a tie
wrap through the slot and secure to the USB cable when it is connected to the device.

USB connector

The USB connector provides +5 V power and communication. The voltage supplied through the USB connector
is system-dependent, and may be less than 5 V. No external power supply is required.

LED

The LED indicates the device status. When connected to a USB port, the LED blinks steadily to indicate that
the device is initialized and receiving power. Refer to the following table for the possible LED states.
LED state
Not lit
Continuous single-blink
Continuous double-blink

Connecting wires to the spring terminals

Use a flathead screwdriver with a blade smaller than 2.3 x 1.0 mm (0.09 x 0.04 in.) to connect wires to the
detachable spring terminal connectors. Use 18 to 28 AWG copper conductor wire with 7 mm (0.28 in.) of
insulation stripped from the end when wiring connections.
Insert the screwdriver into the spring clamp activation slot and press a wire into the corresponding connector
terminal, then remove the screwdriver to clamp the wire into the terminal.
Distributed by MicroDAQ.com, Ltd.
/
EX+ EX–
6-position spring terminal assignments per input mode
Bridge
Current
Full Half
HI EX+ EX+
— HI HI
LO EX– EX–
— LO LO
LED state/device status
Device status
The device is not connected to a USB port or hub.
The device is operating normally.
The device is operating normally. (Connected to a USB 1.1 port or hub.)
Figure 4. Connecting a wire to the spring terminal connector
)-if the sensor requires a separate excitation connection.
Resistance
Quarter 2-wire
HI
—
LO
—
11
www.MicroDAQ.com
Functional Details
).
HI
LO ).
RTD
4-wire 4-wire 3-wire
EX+ EX+
HI —
EX– EX–
LO LO
(603) 746-5524