Honeywell DCP552 Mark II Manual Operation and Auto-Tuning, Manual operation, Auto-tuning AT

Chapter 6. OPERATION

6 - 5 Manual Operation and Auto-Tuning

■Manual operation

When outputs are indicated in the basic display status, only one digit in the output value flashes. Increasing or decreasing the output value using ↑ and ↓ keys causes the actual output to change accordingly. Unlike setting registration, there is no need to press the ENTER key.

Use the ← and → keys to move the flashing digit.

Setup data C35 is used to select smooth and preset output changes when going from AUTO to MANUAL modes.

Changes from MANUAL to AUTO are smooth.

(Note, however, that when the integral time setting for a PID group PID parameter of 0 may cause abrupt changes.)

■Auto-tuning (AT)

Set values can automatically be written when using auto-tuning (AT) in the RUN, HOLD, FAST and END modes during AUTO mode operation and PID groups (1 to 9, A1 to A7 or fixed command control) are being used.

In READY AUTO mode, the tuning points of PID parameters tP-A1to tP-A7settings can be used as SP to perform auto-tuning of PID groups A1 to A7 values. Variable parameter PA08 (CH1) and PA93 (CH2) allow the following selections:

0: AT is not performed.

1: A general AT operation of a PID group used in a mode other than READY mode

2: AT of PID values that do not easily overshoot can be written to a PID group used in a mode other than READY mode.

3: A standard AT operation is repeatedly performed on PID groups A1 to A7 in READY mode.

4: Repeated AT of PID values that do not easily overshoot can be written to PID groups A1 to A7 used in READY mode.

•During auto-tuning, program run time stops. Thus the RUN and FAST modes are changed to the HOLD mode.

•Auto-tuning always calculates the excess time and limit sensitivity of thread for two limit cycles and calculates PID values using characteristics equations, then automatically writes the results.

•The setup data C21 setting (CH1) and C22 setting (CH2) change the upper and lower output limit used during auto-tuning.

A setting of 1, 3 or 5 causes the lower output limit to be determined by variable parameter PA09 and the upper output limit to be determined by PA10.

A setting of 2 or 4, lower output limit is off and the upper output limit is on.

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