Rockwell Automation 1426 PowerMonitor 5000 Unit - Manual (Page 159)

Rockwell Automation Publication 1426-UM001F-EN-P - November 2013 159
Logic Functions Chapter 7
Simple Setpoint Logic (all models)
The PowerMonitor 5000 unit provides three test conditions for setpoint logic.
Any parameter type is permitted to be used with any test condition. Be sure to
test the operation of your setpoint setup to assure the desired operation.
Greater Than
A Greater Than setpoint test condition arms the setpoint for activation when the
monitored value is greater than the threshold, and dis-arms the setpoint when the
value is less than the threshold less the hysteresis value.
Figure 23 illustrates this.
In Figure 23 , the setpoint is armed at point A, dis-armed at point B, and armed at
point C. Points d and f also arm the setpoint but the value decreases below the
threshold at points e and g before the assert delay time passes.
Figure 23 - Greater Than Test Condition
Less Than
A Less Than test condition arms the setpoint for activation when the monitored
value is less than the threshold, and dis-arms the setpoint when the value is
greater than the threshold plus hysteresis.
Figure 24 illustrates this. In Figure 24 ,
the setpoint is armed at point A, dis-armed at point B, and armed at point C.
Points d and f also arm the setpoint but the value increase above the threshold at
points e and g before the assert delay time passes.
Figure 24 - Less Than Test Condition
Threshold
Hysteresis
Assert
Delay
Deassert
Delay
Setpoint
Status
A
B
C
a
b
c
d
e f
g
Assert
Delay
1
0
Selected
Parameter
Threshold
Assert
Delay
Deassert
Delay
Setpoint
Status
Assert
Delay
1
0
Selected
Parameter
A
B
C
a
b
c
d
e f
g
Hysteresis