Despatch DES2000 Controller - Manual (Page 11)

5
Table 2 Operating Parameter Outline
Code Name Settings
CtL Control Mode PID
At Auto-tuning OFF
P * Proportional Band 5 **
I Integral Time 120
d Derivative Time 0
Ct Cycle Time 1
FL Input Filter 2
bS PV Bias (Offset) 0
LoC Key Lock 0
* If P is not displayed the Control Mode (CtL)
must be first set to Pid.
** For F change to value 13.
Definitions for Table 2:
CtL Control Mode - This parameter determines whether controller functions as a time
proportional or an on/off control.
At
Auto-tuning
– Off for PID tuning, ON for controller to tune process.
P
Proportional Band - Expressed in degrees. This value determines the band width on
both sides of the setpoint within which the control provides proportional control.
I
Integral Time - Expressed in seconds. This parameter corrects for errors in actual
temperature versus the setpoint.
D
Derivative Time - Expressed in seconds. This effect of the derivative time is in direct
proportion to the time setting.
Ct
Cycle Time - Expressed in seconds. This is the total time for one ON/OFF cycle of the
controller output during the proportional action.
FL
Input Filter
– Expressed in seconds. This function should be used when the PV may
fluctuate greatly (i.e. input signal contains noise).
bS
PV Bias - Expressed in percent of span. From –100 to 100% of span, this parameter
used to set the actual oven temperature to the controller display.
LoC
Key Lock - This provides levels of access to the controller.
0 = No key lock, full access to controller.
1 = Prevents changing of all parameters except setpoint.
2 = Prevents all parameters from being changed including the setpoint.
–1 = Set to enter the Setup parameter setting display.
When LoC = -1, the parameters are displayed in the order shown in the Set-Up
Parameters section, below.