Measurement Computing USB-1208HS-4AO - Manual (Page 11)

USB-1208HS-4AO User's Guide Functional Details
11
USB connector
The USB connector provides +5 V power and communication. No external power supply is required.
Activity LED
The Activity LED indicates the communication status of the USB-1208HS-4AO. It blinks when data is
transferred, and is off when the device is not communicating. This LED uses up to 10 mA of current and cannot
be disabled.
Status LED
The Status LED turns on when the device is detected and installed on the computer.
Signal connections
Analog input
You can connect up to eight analog input connections to the screw terminals labeled AIN0 through AIN7 .
Analog signals are referenced to analog ground (AGND).
Single-ended mode requires two wires:
 The wire carrying the signal to be measured connects to AINx.
 The second wire connects to AGND.
Differential mode requires two wires plus a ground reference:
 The wire carrying the positive portion of the differential signal to be measured connects to AINx.
 The wire carrying the negative portion of the differential signal to be measured connects to AIN(x+1).
 The analog ground reference wire connects to AGND.
The terminal configurations for single-ended and differential modes are shown in the table below.
Channel # 8 single-ended channels configuration 0 4 differential channels configuration
Vin+ Vin– Vin+ Vin–
0 AIN0 AGND AIN0 AIN1
1 AIN1 AGND AIN2 AIN3
2 AIN2 AGND AIN4 AIN5
3 AIN3 AGND AIN6 AIN7
4 AIN4 AGND - -
5 AIN5 AGND - -
6 AIN6 AGND - -
7 AIN7 AGND - -
In single-ended mode, the input voltage ranges are ±10 V, ±5 V, ±2.5 V, 0 to 10 V. In differential mode, the
input voltage ranges are ±20 V, ±10 V, and ±5 V. The voltage level on each AINx input is limited to ±14 V