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PRESYS
| Instruments
Compute the optimum PID parameter adjustment according to the table below:
Control action
P
P + I
P + D
P + I + D
PID Adjustment under the heating-cooling mode
Select the heating-cooling control mode (HC) in level 5. Assign the derivative time
(DER) with the value obtained from the table. Set the heating integrative rate value
(H.Int) to the same value of the cooling integrative rate (C.Int), and both equal to the
value obtained from the above table. Note that the equality between derivative time and
the integrative rate for the heating and cooling action are justified by the fact that both
actuate on the same process and are both related to the process oscillation period. The
same does not apply to gain. Therefore, the heating gain may be obtained from the
above table, but the cooling gain should be manually adjusted until the best system
performance is achieved.
3.2.7 - Level 7 - SetP (Programmable Setpoint)
The DCY-2050 / 2051controllers can run a program which generates, repeatedly,
up to ten setpoint values.
The setpoint values, the time taken to reach these values and the number of
times this setpoint sequence should be repeated are parameters selected by the user
within Configuration level 7.
Figure 30 shows an illustration of a wave form obtained from the setpoints
programmed by the user. Note that the first setpoint (SP-1) is reached from the local
setpoint and that after running the programmable setpoint the value to be used for the
local setpoint will be the last value obtained by the programmable set-point.
The options of level 7 are shown on figure 31, below.
Gain
0.5 Ku
0.45 Ku
0.6 Ku
0.6 Ku
Fig. 30 - Evolution of the programmable setpoint
DCY-2050 and DCY-2051
Integrative Rate
(INT)
-
1/(0.83 Pu*)
-
1/(0.5 Pu)
Derivative time
(DER)
-
-
0.125 Pu
0.125 Pu
* Pu - given in minutes
Operation
Page 47
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