Digital I/O Terminals (Dio0 - Dio3); Power Terminals - Measurement Computing miniLAB 1008 User Manual

miniLAB 1008 User's Guide
CHHI
-20 V
-15 V
-10 V
-10 V
0 V
0 V
+10 V
+10 V
+15 V
+20 V
Additional information on analog signal connections
For general information regarding single-ended and differential inputs, refer to the Guide to Signal Connections
(available on our web site at www.mccdaq.com/signals/signals.pdf).

Digital I/O terminals (DIO0 - DIO3)

Connect up to four digital I/O lines to the screw terminals containing pins
diagrams on page 3-5 for the location of these pins. You can configure each digital channel independently for
either input or output.
Overvoltage/short circuit protection is provided with a 1.5 kΩ series resistor on each I/O pin. Use of the resistor
may limit the value of the output current, however. For example, if the output current is 1 mA, the resistor drops
1.5 V, resulting in an output of 3.5 V.
You can use the digital I/O terminals to detect the state of any TTL level input. In Figure 3-8, if the switch is set
to the +5 V input, and the DIO0 reads TRUE (1). If the switch is moved to GND, the DIO0 reads FALSE.
Additional information on digital signal connections
For general information regarding digital signal connections and digital I/O techniques, refer to the Guide to
Signal Connections (available on our web site at www.mccdaq.com/signals/signals.pdf).

Power terminals

The connections on the screw terminal draw power from the USB connector. The +5 V screw terminal
PC +5V
is a 5 volt output that is supplied by the computer.
Caution! The PC +5V terminals are outputs. Do not connect an external power supply to a +5 V screw
terminal, or you may damage the device and possibly the computer.
The maximum total output current that can be drawn from all miniLAB 1008 connections (power, analog and
digital outputs) is 500 mA. This maximum applies to most personal computers and self-powered USB hubs.
Bus-powered hubs and notebook computers may limit the available output current to 100 mA.
Table 3-3. Sample inputs and differential results
CHLO
0 V
+5 V
0 V
+10 V
+10 V
+20 V
-10 V
0 V
-5 V
0
+GND
Figure 3-8. Digital connection DIO0 detecting the state of a switch
Result
Invalid
Invalid
-10 V
-20 V
-10 V
-20 V
+20 V
+10 V
+20 V
+20 V
DIO0
DIO0
+5V
3-8
Functional Details
to . Refer to the pinout
DIO3