Honeywell UDC 3300 manual Time, Position, or Current Proportional Simplex Control

11.2 Time, Position, or Current Proportional Simplex Control

Procedure	The procedure listed in Table 11-1 gives you the steps for manually tuning
	a controller with Time, Position, or Current proportional simplex control.
	Table 11-1 Manual Tuning Procedure for Simplex Control

Step

1

2

3

4

5

6

Action

In Manual Mode, adjust the output to bring the PV (Process Variable) near the desired value.

Set the Rate time to 0 minutes and set the Reset time to the maximum value (50.00 minutes) or set repeats/min to the minimum value to minimize reset action

If applicable, set the CYCLE TIME to 4 seconds and DEADBAND to 0.5.

Increase GAIN (decrease PB) significantly. Try a factor of 10.

Adjust the local setpoint to equal PV and switch to Automatic control mode.

Increase the setpoint by 5 or 10% and observe the process variable response.

If the PV oscillates, continue to Step 7. If it does not oscillate, return to the original setpoint and increase GAIN (decrease PB) again by a factor of 2, and repeat Step 5.

7

Compare the oscillations with the figure below:

ProcessVariable	Pattern A	Pattern B
	Time for one cycle
	Amplitude
		Time

Pattern C

20778

8

9

•If the oscillation matches pattern A, go to Step 8.

•If the oscillation matches pattern B, increase GAIN (decrease PB) by a factor of 2 and repeat Steps 4 to 6.

•If the oscillation matches pattern C, decrease GAIN (increase PB) by a factor of 0.8 and repeat Steps 4 to 6

The amplitude of the cycle is immaterial, but all of the elements of the loop must be within the operating range (i.e., the valve must not go full open or closed).

Record the current value of GAIN (or PB) and measure and record the value of time for one completed oscillation of PV.

Select the proper set of formulas from Table 11-2. Use the values of Gain (or PB) and time (in minutes) in the formulas to arrive at the controller’s tuning parameters settings.

274 UDC 3300 Controller Product Manual 4/00