WEG CFW-09 User Manual page 223

CHAPTER 6 - DETAILED PARAMETER DESCRIPTION
Parameter
P525
Keypad PID Setpoint
P526
Process Variable
Filter
P527
PID Action Type
224
Range
[Factory Setting]
Unit Description / Notes
After the feedback input has been chosen, you must set the input function
selected at P237 (to AI2) or P241 (to AI3).
Feedback Type:
The PID action Type described above considers that the variable feedback
signal increases when the process variable also increases (direct
feedback). This is the most common used feedback type.
When the process variable feedback decreases when the process variable
increases (inverse feedback), it is required to program the selected
analog input for the PID (AI2 or AI3) as inverse reference: P239 = 2 [(10
to 0) V/(20 to 0) mA] or P239 = 3 [(20 to 4) mA]. When the feedback is
through AI2 and P243 = 2 [(10 to 0) V/(20 to 0) mA] or P243 = 3 [(20 to
4) mA] when the feedback is through AI3. When this setting is not
present, PID does not operate correctly.
0.0 to 100.0
It provides the setpoint via the
[ 0.0 ]
(P203 = 1) provided that P221 = 0 (LOC) or P222 = 0 (REM) and the
0.1 %
inverter is in the Automatic mode. If it has been set to Manual Mode,
the speed reference is given by P121.
The value of P525 is maintained at the last set value (backup), even
when inverter is disabled or enabled with [P120 = 1 (Active)].
Once PID is in Automatic mode, the Setpoint value for PID regulator is
entered into the CFW-09 via any reference set by P221 (LOCAL mode)
or P222 (REMOTE mode). Particularly, most of general PID applications
uses the setpoint via the AI1 [P221 = 1 (LOC) or P222 = 1(REM)] or via
the
figure 6.47 - Block Diagram of the PID Regulator.
0.0 to 16.0 It sets the time constant of the Process Variable Filter.
[ 0.1 ]
Generally 0.1 will be a suitable value, excepting the process variable
0.1 s
signal has a too high noise level. In this case, increase this value
gradually by checking the result.
0 or 1 It defines the control action type:
[ 0 ]
-
and keys [P221 = 0 (LOC) or P222 = 0 (REM)]. Refer to
P527
0
1
Table 6.67 - PID action type
and keys for the PID Regulator
Action Type
Direct
Reverse