Rockwell Automation 5370-CVIM2 Module - Manual (Page 476)

5 Chapter Chapter 9
Discrete I/O Assignments
9–13
+/– Selections
As described earlier, the +/– field selects additional parameters for the
discrete inputs and outputs, as follows:
For inputs signals ( System I/O only), the +/– parameter determines (when
the CVIM2 system is online) whether the system will respond to an
off–to–on change in the trigger input line (
Pos ), or to an on–to–off change in
the input line ( Neg ). Pick the appropriate box under the +/– heading to
toggle “ Pos ” to “ Neg ,” or vice versa, for a particular input signal.
If an I/O interface board is being used, you can determine the input line state
by looking at the corresponding LED on the JMB board: Thus, the input line
state is on when the corresponding LED on the JMB board is on, and vice
versa. Figure 9.8 shows these relationships.
Figure 9.8 Example: Effects of +/– Settings on Trigger Signal Detection
System detects
trigger signal
here
Off
On
+/– = Neg
System detects
trigger signal
here
Off
On
+/– = Pos
System detects
trigger signal
here
Off
On
+/– = Pos
System detects
trigger signal
here
Off
On
+/– = Neg
Input line state
Input line state
Input line state
Input line state