Installation manual

Series C Controller Configuration and Operation Manual
16-4  Athena Controls, Inc. 900M050U00
16.3 Manual Tuning (Zeigler-Nichols PID Method)
16.3.1 Introduction
This tuning method may be used for non-temperature control processes or if the spread
between initial process temperature and process operating temperature is small. This
manual tuning process requires that the PV be tracked over time. If the controller is
equipped with an auxiliary analog output card, connect a chart recorder to its terminals,
and use the A.outA.out (auxiliary output) menu to specify that the PV will be retransmitted. If
the controller is not equipped with an auxiliary analog output, you can graph the
displayed PV against time manually.
The procedure below is used to do manual tuning using the front panel of a 16C, 18C, or
25C controller. You can use a Multi-Comm host or a MODBUS master to change the
mode, and to view and change tuning parameter values for the 1ZC, 16C, 18C, and 25C
controllers.
16.3.2 Procedure
To perform manual tuning:
1. For heat/cool control processes, disable any cooling device used or set the output
type parameter (in the OutPOutP (output) menu) for this direct-acting output to off.
(Usually, output 2 is used for cooling, so you would set O2.tYO2.tY = OFFOFF.)
2. With the power off and the controller NOT in the Key Lockout security level, apply
power and immediately put the controller in standby mode by pressing the key
until CtrLCtrL is displayed on the top line (after approximately three seconds) and the
current mode on the lower line. Press the or key to cycle through the
modes until StbYStbY is on the lower line. Press the key again (briefly). The display
will show StbYStbY alternating with the process value on the top line, and the setpoint
displayed steadily on the lower line.
3. Enter the process setpoint using the and keys.
4. Make sure the PbPb (proportional band) is set to its maximum value, and that derder
(derivative / rate action), OFFSOFFS (manual reset), and IntInt (integral offset / auto reset)
are all set to zero. To access the menu system, press and hold the key until a
menu name abbreviation is displayed on the top line. Press the key repeatedly
until the CtrLCtrL menu is reached. Step through the tuning parameters using the
key. To change values, use the and keys, then press to write the new
value to the controller’s database.
5. Put the controller in normal (automatic) mode by pressing the key until CtrLCtrL is
displayed on the top line (after approximately three seconds) and the current mode
on the lower line. Press the or key to cycle through the modes until nornor is
on the lower line. Press the key again (briefly). The display will show the
process value on the top line and the setpoint on the lower line.