BNC 725 - Manual (Page 20)

20
Experimenting With Channel Logic
This brief example will show you more about channel logic:
1. Connect a normally-open switch to Input 1 and another to Input 2.
2. Connect an LED to Output A.
3. Open the Channel Settings screen for Channel A.
4. Choose Output = Input from the Timing Mode list. In this mode, the output of Channel
A is always the same as its input.
5. Select the Passive tab and choose Output = Input.
6. Select the Logic tab and enter:
inA = in1;
7. Click the Set All Channels button.
The LED at Output A should be glowing, indicating that the output is TRUE, or HIGH (since
Model 725 inputs are normally HIGH). When you close Switch 1, the LED will turn off,
indicating that the output is FALSE, or LOW.
NOTE: The Channel A LED on the front of the Model 725 glows green while the
channel output is LOW, or red when the output is HIGH. The channel LED does not
always indicate the channel’s output state—only in certain Timing Modes. You’ll learn
more later in the Timing Modes section.
8. Next, change the logic assignment to:
inA = not in1;
9. Click the Set All Channels button. The LED at Output A will now remain off until you
close the switch.
10. Change the logic assignment to:
inA = not in2;
11. Click the Set All Channels button. The LED at Output A will now remain off until you
close Switch 2.