Ramp and soak profile program, Auto tune – NOVUS Controller N2000 User Manual
Page 7
NOVUS AUTOMATION
7/9
RAMP AND SOAK PROFILE PROGRAM
Seven ramp and soak profiles with up to 7 segments each can be
programmed. Longer profiles of up to 49 segments can be created by
linking 2 or more profiles.
SP
tim e
T1
T 2
T3
T 4
T5
SP 0
SP 1
SP 2
SP 3
SP4
SP 5
S P6
SP 7
T6
T 7
Figure 11 - Example of a complete ramp and soak profile
To execute a profile with fewer segments just program 0 (zero) for the
time intervals that follow the last segment to be executed.
SV
time
T1
T2
T3
SP0
SP1
SP2
SP3
T4=0
Figure 12 - Example of a profile with fewer segments. (T4 is set 0)
The program tolerance “Ptol
Ptol
Ptol
Ptol” defines the maximum deviation
between PV and SV for the execution of the profile. If this deviation is
exceeded, the program will be interrupted until the deviation falls to
within the tolerance band.
Programming 0 (zero) at this prompt disables the tolerance and the
profile execution will not to be halted even if PV does not follow SV
(time priority as opposed to SV priority).
The ramp and soak event function is used to activate alarms at any
segment of program 1. This applies only to program 1.
LINK OF PROGRAMS
It is possible to create a more complex program, with up to 49
segments, joining the seven programs. This way, at the end of a
program execution the controller immediately starts to run another one.
When a program is created, it must be defined in the “LP
LP
LP
LP" screen
whether there will be or not another program.
To make the controller run a given program or many programs
continuously, it is only necessary to link a program to itself or the last
program to the first.
SV
time
T1
T2
T3
T4
T5
T1
T2
T3
T4
SP0
SP1
SP2
SP3
SP4
SP5 / SP0
SP1 SP2
SP3
SP4
Program 1
Program 2
Fig. 13 - Example of two linked programs
EVENT ALARM
To enable this event function the alarms to be activated must be
selected for rS
rS
rS
rS function and are programmed at the PE
PE
PE
PE 0
0
0
0 to PE
PE
PE
PE 5
5
5
5
prompts. The number to be programmed at the prompt defines the
alarms to be activated (Table 5).
CODE
ALARM 1
ALARM 2
ALARM 3
ALARM 4
0
0
0
0
1
1
1
1
X
2
2
2
2
X
3
3
3
3
X
X
4
4
4
4
X
5
5
5
5
X
X
6
6
6
6
X
X
7
7
7
7
X
X
X
8
8
8
8
X
9
9
9
9
X
X
10
10
10
10
X
X
11
11
11
11
X
X
X
12
12
12
12
X
X
13
13
13
13
X
X
X
14
14
14
14
X
X
X
15
15
15
15
X
X
X
X
Table 5 - Event codes for ramp and soak
To configure and execute a ramp and soak program:
•
Program the tolerance value, SV, time and event.
•
If any event alarm is required program the ramp and soak event
function.
•
Set the control mode to automatic.
•
Select ramp and soak program to be executed at prompt Prn
Prn
Prn
Prn
(0 to 7)
•
Start control at the rvn
rvn
rvn
rvn prompt by selecting YES.
Before executing the program the controller waits for PV to reach the
first set point SP0
SP0
SP0
SP0 if PtoL
PtoL
PtoL
PtoL is different than zero.
Should any power failure occur the controller resumes at the
beginning of the segment it currently is.
AUTO TUNE
During auto tune the process is controlled in ON/OFF mode at the
programmed SetPoint (SV). Depending on the process
characteristics large oscillations above and below SV may occur and
auto tuning may take several minutes to be concluded.
The recommended procedure is as follows:
•
Disable the control output at the rvn
rvn
rvn
rvn prompt by selecting NO.
•
Select auto mode operation at the Avto
Avto
Avto
Avto prompt by selecting YES.
•
Disable the ramp and soak function (select NO) and program a new
SV value other than the present PV (close to the desired set point).
•
Enable auto tuning at the Atvn
Atvn
Atvn
Atvn prompt by selecting YES.
•
Enable the control output at the rvn
rvn
rvn
rvn prompt by selecting YES.
During the auto tune procedure the soft-start function will not operate
and large oscillations will be induced around the setpoint. Make sure the
process can accept these oscillations and fast control output changes.
If auto tuning results are not satisfactory refer to Table 6 for manual
fine tuning procedure.
PARAMETER
RESPONSE
SOLUTION
Slow Response
Decrease
Proportional Band
Large Oscillation
Increase
Slow Response
Incre ase
Integral Rate
Large Oscillation
Decrease
Slow Response or Instability
Decrease
Derivative Time
Large Oscillation
Increase
Table 6 - Suggestions for manual tuning of PID parameters