WEST 8800 User manual

Process controller 8800
Operating manual
English
9499-040-70611
Valid from: 8405

© West Instruments •Printed in Germany
All rights reserved. No part of this document may bereproduced or published in
any form or by any means without prior written permission from the copyright
owner.
A publication of West Instruments, The Hyde Business Park,
Brighton BN2 4JU, England
8800/8840 Configurator
More efficiency in engineering, more overview in operating:
The projecting environment for the West controllers 8800/8840
Description of symbols:
gGeneral information
aGeneral warning
lAttention: ESD sensitive devices
ATTENTION!
Mini Version and Updates on
www.westinstruments.com

8800 process controller 3
Contents
1Mounting ..............................6
2Electrical connections .......................7
2.1 Connecting diagram .......................7
2.2 Terminal connection.........................8
3Operation .............................12
3.1 Front view ............................12
3.2 Behaviour after power-on .....................13
3.3 Operating level ...........................13
3.4 Error list / Mainenance manager .................14
3.5 Self-tuning .............................17
3.5.1 Preparation for self-tuning .......................17
3.5.2 Optimization after start-up or at the set-point ..............18
3.5.3 Selecting the method ( ConF/Cntr/tunE).............18
3.5.4 Self-tuning start .............................22
3.5.5 Self-tuning cancellation ........................22
3.5.6 Acknowledgement procedures in case of unsuccessful self-tuning . 23
3.5.7 Examples for self-tuning attempts ..................24
3.6 Manual self-tuning .........................25
3.7 Second PID parameter set .....................26
3.8 Alarm handling...........................27
3.9 Operating structure.........................29
4Configuration level ........................30
4.1 Configuration survey ....................30
4.2 Configuration parameters ....................31
4.3 Set-point processing ........................49
4.3.1 Set-point gradient / ramp ........................49
4.4 Switching behaviuor ........................50
4.4.1 Standard ( CyCl=0) .........................50
4.4.2 Switching attitude linear ( CyCl=1).................50
4.4.3 Switching attitude non-linear ( CyCl=2)...............51
4.4.4 Heating and cooling with constant period ( CyCl=3)........52

4 8800 process controller
4.5 Configuration examples ......................53
4.5.1 On-Off controller / Signaller (inverse) .................53
4.5.2 2-point controller (inverse) .......................54
4.5.3 3-point controller (relay & relay) ....................55
4.5.4 3-point stepping controller (relay & relay) ...............56
4.5.5 Continuous controller (inverse) .....................57
4.5.6 ∆-Y - Off controller / 2-point controller with pre-contact ......58
4.5.7 8800 process controller with measured value output ..........59
4.5.8 Continuous controller with integrated positioner ( Cntr/C.Fnc =6)60
5Parameter setting level ......................61
5.1 Parameter survey ........................61
5.2 Parameters .............................62
5.3 Input scaling ............................65
5.3.1 Input Inp.1 and InP.3 .............65
5.3.2 Input InP.2...............................66
6Calibration level .........................67
7Special functions .........................70
7.1 DAC®– motor actuator monitoring ...............70
7.2 O2measurement ..........................72
7.2.1 Connection ...............................72
7.2.2 Configuration: ..............................73
7.3 Linearization ............................74
7.4 8800 process controller as Modbus master ............75
88800/8840 configurator ......................76
9Versions ..............................77
10 Technical data ..........................78
11 Safety hints ............................81
11.1 Resetting to factory setting.....................82
12 Notes ................................83

1Mounting
Safety switch:
For access to the safety switch, the controller must be withdrawn from the
housing. Squeeze the top and bottom of the front bezel between thumb and
forefinger and pull the controller firmly from the housing.
1Factory setting 2Default setting: display of all levels
suppressed, password PASS =OFF
lCaution! The unit contains ESD-sensitive components.
Mounting
8800 process controller 5
or
%
max.
95% rel.
max. 60°C
0°Cmin.
96 (3.78")
48 (1.89")
Loc
min.48 (1.89")
10 (0.4")
1..10
(0.04..0.4")
118 (4.65")
45 +0,6
(1.77" )
+0.02
92
+0,8
(3.62" )
+0.03
*
Ü
*
Ü
security switch
WEST 8800
Process Controller
Loc open Access to the levels is as adjusted by means of 8800/8840 configurator
(engineering tool) 2
closed 1all levels accessible wihout restriction

2Electrical connections
2.1 Connecting diagram
gDependent of order, the controller is fitted with :
wflat-pin terminals 1 x 6,3mm or 2 x 2,8mm to DIN 46 244 or
wscrew terminals for 0,5 to 2,5mm²
Electrical connections
Connecting diagram 6 8800 process controller
1
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(2)
(16)
mA
(mV)
(mV)
Volt
mA
INP2
INP3
INP1
di2
di1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Option
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(16)
OUT1
OUT2
OUT3
OUT4
90...250V
24 V UC
0%
100%
V
V
mA
HC
di2
di3
UT
RXD-B
GND
RXD-A
TXD-B
TXD-A
RS485 RS422
Modbus RTU
RGND
DATA B
DATA A
9
0
8
3
2
17
6
5
4
abcd
e
f
g
a
bc
d
e
+24V DC
24V GND
OUT5
OUT6
!
VP (5V)
DGND
RxD/TxD-N
RxD/TxD-P
PROFIBUS-DP
Schirm/
Screen
5
9
4
8
3
7
2
6
1
5
9
4
8
3
7
2
6
1
390 [
390 [
220 [
DGND
VP (5V)
max.
1200m
Adapter
Profibus DP

2.2 Terminal connection
Power supply connection 1
See chapter 10 "Technical data"
Connection of outputs OUT1/2 2
Relay outputs (250V/2A), potential-free
changeover contact
Connection of outputs OUT3/4 3
arelay (250V/2A), potential-free
changeover contact universal output
bcurrent (0/4...20mA)
cvoltage (0/2...10V)
dtransmitter supply
elogic (0..20mA / 0..12V)
Connection of input INP1 4
Input mostly used for variable x1
(process value)
athermocouple
bresistance thermometer (Pt100/ Pt1000/ KTY/ ...)
ccurrent (0/4...20mA)
dvoltage (0/2...10V)
Connection of input INP2 5
fheating current input (0..50mA AC)
or input for ext. set-point (0/4...20mA)
gpotentiometer input for position
feedback
Connection of input INP2 5
aHeating current input (0...50mA AC)
or input for ext. Set-point (0/4...20mA)
bPotentiometer input for position
feedback
Connection of input INP3 6
As input INP1, but without voltage
Connection of inputs di1, di2 7
Digital input, configurable as switch or
push-button
Electrical connections
8800 process controller 7 Terminal connection
6
9
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
17
(16)
L
N
+
5
43
2
1
8
7
15
2OUT1/2 heating/cooling
L
N
+
_
SSR
3
4
5
6
9
10
11
12
13
14
15
1
2
3
4
5
8
9
10
11
12
13
14
15
17
(16)
2
1
8
7
6
7
Logik
5INP2 current tansformer

Connection of inputs di2/3 8(option)
Digital inputs (24VDC external), galvanically isolated, configurable as switch or
push-button
Connection of output UT9(option)
Supply voltage connection for external energization
Connection of outputs OUT5/6 0(option)
Digital outputs (opto-coupler), galvanic isolated, common positive control
voltage, output rating: 18...32VDC
Connection of bus interface !(option)
PROFIBUS DP or RS422/485 interface with Modbus RTU protocol
gIf the universal output OUT3 or OUT4 is used there may be no external galvanic
connection between measuring and output circuits!
Electrical connections
Terminal connection 8 8800 process controller
13
14
15
Option
17
(16)
1
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(2)
(16)
+24VDC
5mA
5mA
0V
1
2
3
K
+
-
+
-
17,5V
22mA
14
13
+
-
15
OUT3
10
11
12
J
J
89 di2/3, 2-wire transmitter supply

* Interface description Modbus RTU in speperate manual: see page 75.
Electrical connections
8800 process controller 9 Terminal connection
1
2
3
K
+
-
+
-
13V
22mA
13
14
15
11
12 13
17
(16)
14
15
12
11
10
3OUT3 transmitter supply
1
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(2)
(16)
option
1
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(2)
(16)
option
1
3
4
5
6
7
8
9
10
11
12
13
14
15
17
(2)
(16)
option
11
12
13
14
15
10
11
12
13
14
15
10
11
12
13
14
15
RGND RGND RGND
RT
RS485-RS232
converter
PC
DATA A
DATA B
DATA A
DATA B
DATA A
DATA B
J
max. 1000m
"Twisted Pair” cable
10
RT
R=100 Ohm
RGND connection optional
R = 120...200 OhmT
R = 120...200 OhmT
9RS485 interface (with RS232-RS485 interface converter) *

8800 process controller connecting example:
aCAUTION: Using a Limit controller is recommendable in systems
where overtemperature implies a fire hazard or other risks.
Electrical connections
Terminal connection 10 8800 process controller
12
+
_
SSR
+
_
SSR
+
_
SSR
Series connection
Parallel connection
+
_
SSR
+
_
SSR
4V
4V
4V 12V
I =22mA
max
I =22mA
max
12V 11
10
10
11
12
Logic
3OUT3 as logic output with solid-state relay (series and parallel connection)
+
_
L1
L2
N1
N2
fuse fuse fuse
SSR
contactor
heating
+
3
4
5
6
7
8
9
11
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
17
(16)
15
2
1
12
10
Logic
8840 profiler
1
N6700Z21
6700 Limit controller
Standard version:
00
other versions on requestr
6700
Limit
controller
1

3Operation
3.1 Front view
LED colours:
LED 1, 2, 3, 4: yellow
Bargraph: red
other LEDs: red
gIn the upper display line, the
process value is always displayed.
At parameter, configuration,
calibration as well as extended
operating level, the bottom
display line changes cyclically between parameter name and parameter value.
Operation
8800 process controller 11 Front view
(
1
2
3
4
5
6
$
7
8
%
&
(
/
6
7
7
8
3
4
5
9
0
§" !
§"
"
1Status of switching outputs
OuT.1... 6
2Process value display
3Set-point, controller output
4Signals display on °C or °F
5Signals ConF and PArA level
6Signals aktive function key
7Self-tuning active
8Entry in error list
9Bargraph or clear text display
0SP.2 is effective
!SP.E is effective
"Set-point gradient effective
§Manual/automatic switch-over:
Off: Automatic
On: Manual (changing possible)
Blinks:Manual (changing not
possible
(rConF/Cntr/MAn)
$Enter key:
calls up extended operating
level / error list
%Up/down keys:
changing the set-point or the
controller output value
&Manual mode /spec. function
(→ConF /LOGI )
/Freely programmable function
key
(PC connection for
8800/8840 configurator
(engineering tool)

3.2 Behaviour after power-on
After supply voltage switch-on, the unit starts with the operating level.
The unit is in the condition which was active before power-off.
If the 8800 process controller was in manual mode at supply voltage switch-off,
the controller will re-start with the last output value in manual mode at power-on.
3.3 Operating level
The content of the extended operating level is determined by means of 8800/8840
configurator (engineering tool). Parameters which are used frequently or the
display of which is important can be copied to the extended operating level.
Operation
Behaviour after power-on 12 8800 process controller
Ò
Ò
Ù
Ù
Ù
Ù
A
utomat
i
c
Extended operating level
M
anua
l
i
i
only
display
switching
Display
Error list (if error exists)
Y21
1199
1200
1199
È
ÌÈ
Ì
Y21
1199
1200
1199
È
Ì
FbF.1
126
Err
2
126
Err
time
out
time
out
time
out

3.4 Error list / Mainenance manager
With one or several errors, the extended operating level
always starts with the error list. Signalling an actual entry
in the error list (alarm, error) is done by the Err LED in the
display. To reach the error list press Ùtwice.
Error list:
Operation
8800 process controller 13 Error list / Mainenance manager
°C
°F
Err LED status Signification Proceed as follows
blinks
(status 2)Alarm due to existing
error -Determine the error type in the error list
-After error correction the unit changes to status 1
lit
(status 1)Error removed, alarm
not acknowledged -Acknowledge the alarm in the error list pressing key ÈorÌ
-The alarm entry was deleted (status 0).
off
(status 0)No error, all alarm
entries deleted --Not visible except when acknowledging
Name Description Reason Possible remedial action
E.1 Internal error,
cannot be removed
- E.g. defective EEPROM - Contact West service
- Return unit to our factory
E.2 Internal error, can be
reset - e.g. EMC trouble - Keep measurement and power supply
cables in separate runs
- Ensure that interference suppression
of contactors is provided
E.3 Configuration error,
can be reset
- wrong configuration
- missing configuration
- Check interaction of configuration /
parameters
E.4 Hardware error - Codenumber and
hardware are not
identical
- Contact West service
- Elektronic-/Optioncard must be
exchanged
FbF.1 Sensor break INP1 -Sensor defective
-Faulty cabling
-Replace INP1 sensor
-Check INP1 connection
Sht.1 Short circuit INP1 -Sensor defective
-Faulty cabling
-Replace INP1 sensor
-Check INP1 connection
POL.1 INP1polarity error -Faulty cabling -Reverse INP1 polarity
FbF.2 Sensor break INP2 -Sensor defective
-Faulty cabling
-Replace INP2 sensor
-Check INP2 connection
Sht.2 Short circuit INP2 -Sensor defective
-Faulty cabling
-Replace sensor INP2
-Check INP2 connection
POL.2 INP2 polarity -Faulty cabling -Reverse INP2 polarity
FbF.3 Sensor break INP3 -Sensor defective
-Faulty cabling
-Replace INP3 sensor
-Check INP3 connection
Sht.3 Short circuit INP3 -Sensor defective
-Faulty cabling
-Replace sensor INP3
-Check INP3 connection
POL.3 INP3 polarity -Faulty cabling -Reverse INP3 polarity

Operation
Error list / Mainenance manager 14 8800 process controller
Name Description Reason Possible remedial action
HCA Heating current
alarm (HCA) -Heating current circuit
interrupted, I< HC.A or
I> HC.A (dependent of
configuration)
-Heater band defective
-Check heating current circuit
-If necessary, replace heater band
SSr Heating current
short circuit (SSR) -Current flow in heating
circuit with controller
off
-SSR defective
-Check heating current circuit
-If necessary, replace solid-state relay
LooP Control loop alarm
(LOOP) -Input signal defective or
not connected correctly
-Output not connected
correctly
-Check heating or cooling circuit
-Check sensor and replace it, if
necessary
-Check controller and switching
device
AdA.H Self-tuning heating
alarm
(ADAH)
-See Self-tuning heating
error status
-see Self-tuning heating error status
AdA.C Self-tuning heating
alarm cooling
(ADAC)
-See Self-tuning cooling
error status
-see Self-tuning cooling error status
LiM.1 stored limit alarm 1 - adjusted limit value 1
exceeded
- check process
Lim.2 stored limit alarm 2 - adjusted limit value 2
exceeded
- check process
Lim.3 stored limit alarm 3 - adjusted limit value 3
exceeded
- check process
Inf.1 time limit value
message - adjusted number of
operating hours reached
- application-specific
Inf.2 duty cycle message
(digital ouputs)
- adjusted number of duty
cycles reached
- application-specific
E.5
Internal error in DP
module -self-test error
-internal communication
interrupted
-Switch on the instrument again
-Contact West service
dp.1
No access by bus
master -bus error
-connector problem
-no bus connection
-Check cable
-Check connector
-Check connections
dp.2 Faulty configuration -Faulty DP
configuration telegram
-Check DP configuration telegram in
master
dp.3 Inadmissible
parameter setting
telegram sent
-Faulty DP parameter
setting telegram
-Check DP parameter setting
telegram in master
dp.4
No data
communication -Bus error
-Address error
-Master stopped
-Check cable connection
-Check address
-Check master setting

gSaved alarms (Err-LED is lit) can be acknowledged and deleted with the digital
input di1/2/3, the è-key or the Ò-key.
Configuration, see page 37: ConF /LOGI /Err.r
gIf an alarm is still valid that means the cause of the alarm is not removed so far
(Err-LED blinks), then other saved alarms can not be acknowledged and deleted.
Self-tuning heating ( ADA.H) and cooling ( ADA.C) error status:
DAC function ( DAC) error status:
Operation
8800 process controller 15 Error list / Mainenance manager
Error
status Description Behaviour
0No error
3Faulty control action Re-configure controller (inverse idirect)
4No response of process
variable The control loop is perhaps not closed: check sensor, connections and process
5Low reversal point Increase ( ADA.H) max. output limiting Y.Hi or decrease
(ADA.C) min. output limiting Y.Lo
6Danger of exceeded
set-point (parameter
determined)
If necessary, increase (inverse) or reduce (direct) set-point
7Output step change
too small (∆y > 5%) Increase ( ADA.H) max. output limiting Y.Hi or reduce
(ADA.C) min. output limiting Y.Lo
8Set-point reserve too
small Acknowledgment of this error message leads to switch-over to automatic mode.If self-tuning shall be continued,
increase set-point (invers), reduce set-point (direct)
or decrease set-point range
(rPArA /SEtp /SP.LO and SP.Hi )
9Impulse tuning failed The control loop is perhaps not closed: check sensor, connections
and process
Error
status Description Behaviour
0No error
3Output is blocked Check the drive for blockage
4Wrong method of operation Wrong phasing, defect motor capacitor
5Fail at Yp measurement Check the connection to the Yp input
6Calibration error Manual calibration necessary

3.5 Self-tuning
For determination of optimum process parameters, self-tuning is possible.
After starting by the operator, the controller makes an adaptation attempt,
whereby the process characteristics are used to calculate the parameters for fast
line-out to the set-point without overshoot.
The following parameters are optimized when self-tuning:
Parameter set 1:
Pb1 - Proportional band 1 (heating) in engineering units [e.g. °C]
ti1 - Integral time 1 (heating) in [s]
ronly, unless set to OFF
td1 - Derivative time 1 (heating) in [s]
ronly, unless set to OFF
t1 - Minimum cycle time 1 (heating) in [s]
ronly, unless Adt0 was set to “no self-tuning” during
configuration by means of 8800/8840 configurator®.
Pb2 - Proportional band 2 (cooling) in engineering units [e.g. °C]
ti2 - Integral time 2 (cooling) in [s]
ronly, unless set to OFF
td2 - Derivative time 2 (cooling) in [s]
ronly, unless set to OFF
t2 - Minimum cycle time 2 (cooling) in [s]
ronly, unless Adt0 was set to “no self-tuning” during
configuration by means of 8800/8840 configurator®.
Parameter set 2: analogous to parameter set 1 (see page25)
3.5.1 Preparation for self-tuning
wAdjust the controller measuring range as control range limits. Set values
rnG.L and rnG.H to the limits of subsequent control.
(ConfigurationrControllerrlower and upper control range limits)
ConF rCntr rrnG.L and rnG.H
wDetermine which parameter set shall be optimized.
-The instantaneously effective parameter set is optimized.
rActivate the relevant parameter set (1 or 2).
wDetermine which parameter set shall be optimized (see tables above).
wSelect the self-tuning method
see chapter 3.5.3
-Step attempt after start-up
-Pulse attempt after start-up
-Optimization at the set-point
Operation
Self-tuning 16 8800 process controller

3.5.2 Optimization after start-up or at the set-point
The two methods are optimization after start-up and at the set-point.
As control parameters are always optimal only for a limited process range,
various methods can be selected dependent of requirements. If the process
behaviour is very different after start-up and directly at the set-point, parameter
sets 1 and 2 can be optimized using different methods. Switch-over between
parameter sets dependent of process status is possible (see page 25).
Optimization after start-up: (see page25 )
Optimization after start-up requires a certain separation between process value
and set-point. This separation enables the controller to determine the control
parameters by evaluation of the process when lining out to the set-point.
This method optimizes the control loop from the start conditions to the set-point,
whereby a wide control range is covered.
We recommend selecting optimization method “Step attempt after start-up”
with tunE = 0 first. Unless this attempt is completed successfully, we
recommend a “Pulse attempt after start-up”.
Optimization at the set-point: (see page 18)
For optimizing at the set-point, the controller outputs a disturbance variable to the
process. This is done by changing the output variable shortly. The process value
changed by this pulse is evaluated. The detected process parameters are
converted into control parameters and saved in the controller.
This procedure optimizes the control loop directly at the set-point. The advantage
is in the small control deviation during optimization.
3.5.3 Selecting the method ( ConF/Cntr/tunE)
Selection criteria for the optimization method:
Step attempt after start-up Pulse attempt after start-up Optimization at the set-point
tunE =0 sufficient set-point reserve is
provided sufficient set-point reserve is not provided
tunE =1 sufficient set-point reserve is
provided sufficient set-point reserve is not provided
tunE =2 always step attempt after
start-up
Sufficient set-point reserve:
inverse controller: (with process value < set-point- (10% of rnGH -rnGL)
direct controller: (with process value > set-point + (10% of rnGH -rnGL)
Step attempt after start-up
Condition: - tunE = 0 and sufficient set-point reserve provided or
-tunE =2
The controller outputs 0% correcting variable or Y.Lo and waits, until the process
is at rest (see start-conditions on page 16).
Subsequently, a correcting variable step change to 100% is output.
Operation
8800 process controller 17 Self-tuning

The controller attempts to calculate the optimum control parameters from the
process response. If this is done successfully, the optimized parameters are taken
over and used for line-out to the set-point.
With a 3-point controller, this is followed by “cooling”.
After completing the 1st step as described, a correcting variable of -100% (100%
cooling energy) is output from the set-point. After successfull determination of
the “cooling parameters”, line-out to the set-point is using the optimized
parameters.
Pulse attempt after start-up
Condition: - tunE = 1 and sufficient set-point reserve provided.
The controller outputs 0% correcting variable or Y.Lo and waits, until the process
is at rest (see start conditions page 16)
Subsequently, a short pulse of 100% is output (Y=100%) and reset.
The controller attempts to determine the optimum control parameters from the
process response. If this is completed successfully, these optimized parameters
are taken over and used for line-out to the set-point.
With a 3-point controller, this is followed by “cooling”.
After completing the 1st step as described and line-out to the set-point, correcting
variable "heating" remains unchanged and a cooling pulse (100% cooling energy)
is output additionally. After successful determination of the “cooling
parameters”, the optimized parameters are used for line-out to the set-point.
Optimization at the set-point
Conditions:
wA sufficient set-point reserve is not provided at self-tuning start (see page 17).
wtunE is0or1
wWith Strt =1configured and detection of a process value oscillation by
more than ±0,5% of (rnG.H -rnG.L) by the controller, the control
parameters are preset for process stabilization and the controller realizes an
optimization at the set-point (see figure “Optimization at the set-point”).
wwhen the step attempt after power-on has failed
wwith active gradient function ( PArA/SETP/r.SP≠OFF), the set-point
gradient is started from the process value and there isn't a sufficient set-point
reserve.
Operation
Self-tuning 18 8800 process controller

Optimization-at-the-set-point procedure:
The controller uses its instantaneous parameters for control to the set-point. In
lined out condition, the controller makes a pulse attempt. This pulse reduces the
correcting variable by max. 20% 1, to generate a slight process value
undershoot. The changing process is analyzed and the parameters thus calculated
are recorded in the controller. The optimized parameters are used for line-out to
the set-point.
With a 3-point controller, optimization for the “heating“ or “cooling” parameters
occurs dependent of the instantaneous condition.
These two optimizations must be started separately.
1If the correcting variable is too low for reduction in lined out condition it is
increased by max. 20%.
Operation
8800 process controller 19 Self-tuning
set-point
process value
correcting
variable
Optimization at the set-point

Optimization at the set-point for 3-point stepping controller
With 3-point stepping controllers, the pulse attempt can be made with or without
position feedback. Unless feedback is provided, the controller calculates the
motor actuator position internally by varying an integrator with the adjusted
actuator travel time. For this reason, precise entry of the actuator travel time
(tt), as time between stops is highly important. Due to position simulation, the
controller knows whether an increased or reduced pulse must be output. After
supply voltage switch-on, position simulation is at 50%. When the motor actuator
was varied by the adjusted travel time in one go, internal calculation occurs, i.e.
the position corresponds to the simulation:
Simulation actual position
Internal calculation
tt
Internal calculation always occurs, when the actuator was varied by travel time
tt in one go , independent of manual or automatic mode. When interrupting the
variation, internal calculation is cancelled. Unless internal calculation occurred
already after self-tuning start, it will occur automatically by closing the actuator
once.
Unless the positioning limits were reached within 10 hours, a significant
deviation between simulation and actual position may have occurred. In this case,
the controller would realize minor internal calculation, i.e. the actuator would be
closed by 20 %, and re-opened by 20 % subsequently. As a result, the controller
knows that there is a 20% reserve for the attempt.
Operation
Self-tuning 20 8800 process controller