West Control Solutions N8800 User Manual

Process controller 8800

Operating manual

English

9499-040-70611

Valid from: 8405

8800/8840 Configurator

More efficiency in engineering, more overview in operating: The projecting environment for the West controllers 8800/8840

ATTENTION!

Mini Version and Updates on

www.westinstruments.com

Description of symbols:

g General information a General warning l Attention: ESD sensitive devices

© 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

Contents

1 Mounting ..............................6

2 Electrical connections .......................7

2.1 Connecting diagram .......................7

2.2 Terminal connection.........................8

3 Operation .............................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

4 Configuration 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

8800 process controller 3

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

5 Parameter 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

6 Calibration level .........................67

7 Special 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

8 8800/8840 configurator ......................76

9 Versions ..............................77

10 Technical data ..........................78

11 Safety hints ............................81

11.1 Resetting to factory setting.....................82

12 Notes ................................83

4 8800 process controller

1 Mounting

Mounting

min.48 (1.89")

(0.4")

118

WEST

96 (3.78")

Process Controller

48 (1.89")

(4.65")

8800

1..10

(0.04..0.4")

+0,6

(1.77" )

+0.02

Loc

security switch

+0,8

+0.03

max.

(3.62" )

max. 95% rel.

60°C

0°Cmin.

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.

Loc open Access to the levels is as adjusted by means of 8800/8840 configurator

(engineering tool) 2

closed 1 all levels accessible wihout restriction

1 Factory setting 2 Default setting: display of all levels

suppressed, password PASS = OFF

8800 process controller 5

Caution! The unit contains ESD-sensitive components.

Electrical connections

2 Electrical connections

2.1 Connecting diagram

90...250V 24 V UC

OUT1

OUT2

OUT3

OUT4

d b

RGND

DATA B

DATA A

RS485 RS422

Modbus RTU

1 2 3

4 5 6

7 8 9

10 11 12

13 14 15

+24V DC

OUT5 OUT6

24V GND

RXD-B

RXD-A

TXD-B

TXD-A

GND

di2

di3

1 2 3

di1

di2

4 5 6

INP2

8 9

10 11

(mV)

100%

INP3

13 14 15

Volt

INP1

(16)

Option

(2)

(16)

VP (5V)

DGND

RxD/TxD-N

RxD/TxD-P

Schirm/ Screen

PROFIBUS-DP

(mV)

390 [

220 [

Adapter

390 [

DGND

VP (5V)

Profibus DP

max.

1200m

Dependent of order, the controller is fitted with :

flat-pin terminals 1 x 6,3mm or 2 x 2,8mm to DIN 46 244 or

screw terminals for 0,5 to 2,5mm²

Connecting diagram 6 8800 process controller

2.2 Terminal connection

Power supply connection 1

See chapter 10 "Technical data"

Electrical connections

Connection of outputs OUT1/2 2

2 OUT1/2 heating/cooling

Relay outputs (250V/2A), potential-free changeover contact

Connection of outputs OUT3/4 3

a relay (250V/2A), potential-free

changeover contact universal output

b current (0/4...20mA) c voltage (0/2...10V) d transmitter supply e logic (0..20mA / 0..12V)

Connection of input INP1 4

Input mostly used for variable x1 (process value)

a thermocouple b resistance thermometer (Pt100/ Pt1000/ KTY/ ...) c current (0/4...20mA) d voltage (0/2...10V)

10 11 12

13 14 15

10 11 12

13 14

(16)

1 2 3

4 5 6 7 8 9

Connection of input INP2 5

f heating current input (0..50mA AC)

or input for ext. set-point (0/4...20mA)

g potentiometer input for position

feedback

Connection of input INP2 5

a Heating current input (0...50mA AC)

or input for ext. Set-point (0/4...20mA)

b Potentiometer 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

5 INP2 current tansformer

1 2

3 4

5 6

7 8

Logik

10 11 12

13 14 15

10 11 12

13 14 15

(16)

1 2 3

4 5

6 7

8 9

SSR

8800 process controller 7 Terminal connection

Electrical connections

Connection of inputs di2/3 8 (option)

Digital inputs (24VDC external), galvanically isolated, configurable as switch or push-button

Connection of output U

9 (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

89 di2/3, 2-wire transmitter supply

OUT3

10 11

13 14 15

Option

(16)

13 14

+24VDC

17,5V 22mA

5mA

(2)

(16)

If the universal output OUT3 or OUT4 is used there may be no external galvanic connection between measuring and output circuits!

Terminal connection 8 8800 process controller

3 OUT3 transmitter supply

Electrical connections

13V

22mA

10 11

13 14 15

11 12

(16)

13 14

9 RS485 interface (with RS232-RS485 interface converter) *

R = 120...200 OhmT

RGND connection optional

RGND

DATA B

DATA A

option

(2)

(16)

RGND

DATA B

DATA A

option

(2)

(16)

max. 1000m

"Twisted Pair” cable

RGND

DATA B

DATA A

R=100 Ohm

option

(2)

(16)

R = 120...200 OhmT

RS485-RS232

converter

* Interface description Modbus RTU in speperate manual: see page 75.

8800 process controller 9 Terminal connection

Electrical connections

3 OUT3 as logic output with solid-state relay (series and parallel connection)

Series connection

SSR

I =22mA

max

SSR

12V

Logic

SSR

Parallel connection

I =22mA

max

12V

10 11

8800 process controller connecting example:

fuse

8840 profiler

1 2

3 4

5 6

7 8 9

10 11

13 14 15

Logic

10 11 12

13 14

(16)

1 2 3

4 5 6 7 8 9

SSR

fuse

contactor

heating

6700 Limit controller

Standard version: N6700Z21

other versions on requestr

6700 Limit

controller

fuse

CAUTION: Using a Limit controller is recommendable in systems

where overtemperature implies a fire hazard or other risks.

Terminal connection 10 8800 process controller

3 Operation

4 5

7 8

(

9 0

§"

3.1 Front view

Operation

1 Status of switching outputs

OuT.1... 6

2 Process value display 3 Set-point, controller output 4 Signals display on °C or °F 5 Signals ConF and PArA level 6 Signals aktive function key 7 Self-tuning active 8 Entry in error list 9 Bargraph or clear text display 0 SP.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 (r ConF/ 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 )

LED colours:

LED 1, 2, 3, 4: yellow Bargraph: red other LEDs: red

/ Freely programmable function

key

( PC connection for

8800/8840 configurator (engineering tool)

In the upper display line, the process value is always At parameter, configuration, calibration as well as extended operating level, the bottom display line changes cyclically between parameter name and parameter value.

displayed.

8800 process controller 11 Front view

Operation

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.

time

out

utomatic

1199

1200

È Ì

1199

Y21

only

display

anua

1199

Y21

È Ì

1199

1200

È Ì

time

out

Extended operating level

time

out

Error list (if error exists)

126

FbF.1

Err

Behaviour after power-on 12 8800 process controller

Display

switching

126

Err

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 Ù twice.

Err LED status Signification Proceed as follows

blinks

(status 2)

lit

(status 1)

off

(status 0)

Alarm due to existing error

Error removed, alarm not acknowledged

No error, all alarm entries deleted

Determine the error type in the error list

After error correction the unit changes to status 1

Acknowledge the alarm in the error list pressing key ÈorÌ

The alarm entry was deleted (status 0).

-Not visible except when acknowledging

Operation

°C

°F

Error list:

Name

E.1

E.2

E.3

E.4

FbF.1

Sht.1

POL.1 FbF.2

Sht.2

POL.2 FbF.3

Sht.3

POL.3

Internal error, cannot be removed

Internal error, can be reset

Configuration error, can be reset

Hardware error - Codenumber and

Sensor break INP1

Short circuit INP1-Sensor defective

INP1polarity error Sensor break INP2-Sensor defective

Short circuit INP2-Sensor defective

INP2 polarity Sensor break INP3-Sensor defective

Short circuit INP3-Sensor defective

INP3 polarity

Description Reason Possible remedial action

- E.g. defective EEPROM - Contact West service

- Return unit to our factory

- e.g. EMC trouble - Keep measurement and power supply cables in separate runs

- Ensure that interference suppression of contactors is provided

- wrong configuration

- missing configuration

- Check interaction of configuration / parameters

- Contact West service

hardware are not identical

Sensor defective

Faulty cabling

- Elektronic-/Optioncard must be exchanged

Replace INP1 sensor

Check INP1 connection

Replace INP1 sensor

Check INP1 connection

Reverse INP1 polarity

Replace INP2 sensor

Check INP2 connection

Replace sensor INP2

Check INP2 connection

Reverse INP2 polarity

Replace INP3 sensor

Check INP3 connection

Replace sensor INP3

Check INP3 connection

Reverse INP3 polarity

8800 process controller 13 Error list / Mainenance manager

Operation

Name

HCA

SSr

LooP

AdA.H

AdA.C

LiM.1

Lim.2

Lim.3

Inf.1

Inf.2

E.5

dp.1

dp.2

dp.3

Description Reason Possible remedial action

Heating current alarm (HCA)

Heating current circuit

interrupted, I< HC.A or

Check heating current circuit

If necessary, replace heater band

I> HC.A (dependent of configuration) Heater band defective

Heating current short circuit (SSR)

Current flow in heating

circuit with controller

Check heating current circuit

If necessary, replace solid-state relay

off SSR defective

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

Self-tuning heating alarm

See Self-tuning heating

error status

see Self-tuning heating error status

(ADAH) Self-tuning heating

alarm cooling (ADAC)

stored limit alarm 1 - adjusted limit value 1

See Self-tuning cooling

error status

see Self-tuning cooling error status

- check process

exceeded

stored limit alarm 2 - adjusted limit value 2

- check process

exceeded

stored limit alarm 3 - adjusted limit value 3

- check process

exceeded

time limit value message

duty cycle message (digital ouputs)

Internal error in DP module

- adjusted number of operating hours reached

- adjusted number of duty cycles reached

self-test error

internal communication

- application-specific

Switch on the instrument again

Contact West service

interrupted

No access by bus master

bus error

connector problem

no bus connection

Faulty configuration-Faulty DP

configuration telegram

Inadmissible parameter setting telegram sent

Faulty DP parameter setting telegram

Check cable

Check connector

Check connections

Check DP configuration telegram in master

Check DP parameter setting telegram in master

Check cable connection

Check address

Check master setting

dp.4

No data communication

Bus error

Address error

Master stopped

Error list / Mainenance manager 14 8800 process controller

Operation

Saved 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

If 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:

Error status

Description Behaviour

No error

Faulty control action

No response of process variable

Low reversal point Increase ( ADA.H) max. output limiting Y.Hi or decrease

Re-configure controller (inverse i direct) The control loop is perhaps not closed: check sensor, connections

and process

( ADA.C) min. output limiting Y.Lo

Danger of exceeded

If necessary, increase (inverse) or reduce (direct) set-point set-point (parameter determined)

Output step change too small (∆y > 5%)

Set-point reserve too small

Increase ( ADA.H) max. output limiting Y.Hi or reduce

( ADA.C) min. output limiting Y.Lo

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

(r PArA / SEtp / SP.LO and SP.Hi )

Impulse tuning failed The control loop is perhaps not closed: check sensor, connections

and process

DAC function ( DAC) error status:

Error

status

0 3 4 5 6

No error Output is blocked Check the drive for blockage Wrong method of operation Wrong phasing, defect motor capacitor Fail at Yp measurement Check the connection to the Yp input Calibration error Manual calibration necessary

Description Behaviour

8800 process controller 15 Error list / Mainenance manager

Operation

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]

r only, unless set to OFF

td1 - Derivative time 1 (heating) in [s]

r only, unless set to OFF

t1 - Minimum cycle time 1 (heating) in [s]

r only, 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]

r only, unless set to OFF

td2 - Derivative time 2 (cooling) in [s]

r only, unless set to OFF

t2 - Minimum cycle time 2 (cooling) in [s]

r only, 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

Adjust 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 r Cntr r rnG.L and rnG.H

Determine which parameter set shall be optimized.

-The instantaneously effective parameter set is optimized. r Activate the relevant parameter set (1 or 2).

Determine which parameter set shall be optimized (see tables above).

Select the self-tuning method

see chapter 3.5.3

-Step attempt after start-up

-Pulse attempt after start-up

-Optimization at the set-point

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”.

Operation

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

tunE =1

tunE =2

sufficient set-point reserve is

provided

sufficient set-point reserve is

provided

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)

sufficient set-point reserve is not

provided

sufficient set-point reserve is not

provided

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.

8800 process controller 17 Self-tuning

Operation

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:

A sufficient set-point reserve is not provided at self-tuning start (see page 17).

tunE is0or1

With Strt = 1 configured 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”). when the step attempt after power-on has failed

with 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.

Self-tuning 18 8800 process controller

Operation

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.

Optimization at the set-point

set-point

process value

correcting variable

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.

1 If the correcting variable is too low for reduction in lined out condition it is increased by max. 20%.

8800 process controller 19 Self-tuning

Operation

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

Internal calculation always occurs, when the actuator was varied by travel time

tt in one go

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.

, independent of manual or automatic mode. When interrupting the

Self-tuning 20 8800 process controller

3.5.4 Self-tuning start

Start condition:

For process evaluation, a stable condition is required. Therefore, the

controller waits until the process has reached a stable condition after self-tuning start. The rest condition is considered being reached, when the process value

oscillation is smaller than ± 0,5% of (rnG.H - rnG.L). For self-tuning start after start-up, a 10% difference from (SP.LO ... SP.Hi)

is required.

Operation

Self-tuning start can be blocked via 8800/8840 configurator®(engineering tool) ( P.Loc).

Strt = 0 Only manual start by pressing keys Ù and È

simultaneously or via interface is possible.

Strt = 1 Manual start by press keys Ù and È simultaneously

via interface and automatic start after power-on and detection of process oscillations.

Ada LED status Signification

blinks Waiting, until process

calms down

lit Self-tuning is running

off Self-tuning not activ

or ended

°C

°F

3.5.5 Self-tuning cancellation

By the operator:

Self-tuning can always be cancelled by the operator. For this, press Ù and È key simultaneously.With controller switch-over to manual mode after self-tuning start, self-tuning is cancelled. When self-tuning is cancelled, the controller will continue operating using the old parameter values.

By the controller:

If the Err LED starts blinking whilst self-tuning is running, successful self-tuning is prevented due to the control conditions. In this case, self-tuning was cancelled by the controller. The controller continues operating with the old parameters in automatic mode. In manual mode it continues with the old controller output value.

3.5.6 Acknowledgement procedures in case of unsuccessful self-tuning

8800 process controller 21 Self-tuning

Operation

1. Press keys Ù and È simultaneously:

2. Press key Ò (if configured):

3. Press key Ù :

Cancellation causes:

r page 15: "Error status self-tuning heating ( ADA.H) and cooling ( ADA.C)"

The controller continues controlling using the old parameters in automatic mode. The Err LED continues blinking, until the self-tuning error was acknowledged in the error list.

The controller goes to manual mode. The Err LED continues blinking, until the self-tuning error was acknowleged in the error list.

Display of error list at extended operating level. After acknowledgement of the error message, the controller continues control in automatic mode using the old parameters.

Self-tuning 22 8800 process controller

3.5.7 Examples for self-tuning attempts

(controller inverse, heating or heating/cooling)

Operation

Start: heating power switched on

Heating power Y is switched off (1).

When the change of process value X was constant during one minute (2), the power is switched on (3). At the reversal point, the self-tuning

100%

Star t r

t reversal point

attempt is finished and the new parameter are used for controlling to

blinks

set-point W.

Start: heating power switched off

The controller waits 1,5 minutes (1). Heating power Y is switched on (2). At the reversal point, the self-tuning attempt is finished and control to the set-point is using the new parameters.

Self-tuning at the set-point a

100%

start r

blinks

t reversal point

The process is controlled to the set-point. With the control deviation constant during a defined time (1) (i.e. constant separation of process value

and set-point), the controller outputs a reduced correcting variable pulse (max. 20%) (2). After determination of the control parameters using the process characteristic (3), control is started using the new parameters (4).

Three-point controller a

The parameter for heating and cooling are

100%

Start r

blinks

determined in two attempts. The heating power is switched on (1). Heating parameters Pb1, ti1, td1 and t1 are determined at the reversal point. Control to the set-point occurs(2). With constant control deviation, the controller provides a

+100%

Y0%

-100%

Start r

t reversal

point

cooling correcting variable pulse (3). After determining its cooling parameters Pb2, ti2, td2 and t2 (4) from the process characteristics , control operation is started using the new parameters (5).

During phase 3, heating and cooling are done simultaneously!

8800 process controller 23 Self-tuning

Operation

3.6 Manual self-tuning

The optimization aid can be used with units on which the control parameters shall be set without self-tuning. For this, the response of process variable x after a step change of correcting variable y can be used. Frequently, plotting the complete response curve (0 to 100%) is not possible, because the process must be kept within defined limits.

Values T

and x

(step change from 0 to 100 %) or ∆t and ∆x (partial step

max

response) can be used to determine the maximum rate of increase v

100%

max

y = correcting variable

= control range Tu = delay time (s) Tg = recovery time (s) X

max

= maximum process value

Xmax

∆∆x

= max. rate of increase of process value

The control parameters can be determined from the values calculated for delay time T

, maximum rate of increase v

, control range Xhand characteristic K

max

according to the formulas given below. Increase Pb1, if line-out to the set-point oscillates.

Manual self-tuning 24 8800 process controller

Operation

Parameter adjustment effects

Parameter Control Line-out of disturbances Start-up behaviour

Pb1 higherincreased damping slower line-out slower reduction of duty cycle

lower reduced damping faster line-out faster reduction of duty cycle

td1 higherreduced damping faster response to disturbances faster reduction of duty cycle

lower increased

damping

slower response to disturbances

slower reduction of duty cycle

Formulas

K = Vmax * Tu controller behavior Pb1 [phy. units] td1 [s] ti1 [s]

PID 1,7*K 2*Tu 2*Tu With 2-point and 3-point controllers,

the cycle time must be adjusted to

t1 / t2 ≤ 0,25 * Tu

PD 0,5 * K Tu OFF

PI 2,6 * K OFF 6*Tu

PKOFF OFF

3-point-stepping 1,7 * K Tu 2 * Tu

3.7 Second PID parameter set

The process characteristic is frequently affected by various factors such as process value, correcting variable and material differences. To comply with these requirements, the 8800 process controller can be switched over between two parameter sets. Parameter sets PArA and PAr.2 are provided for heating and cooling.

Dependent of configuration ( ConF/LOG/Pid.2), switch-over to the second parameter set ( ConF/LOG/Pid.2) is via one of digital inputs di1, di2, di3, key è or interface (OPTION).

Self-tuning is always done using the active parameter set, i.e. the second parameter set must be active for optimizing.

8800 process controller 25 Second PID parameter set

Operation

3.8 Alarm handling

Max. three alarms can be configured and assigned to the individual outputs. Generally, outputs OuT.1... OuT.6 can be used each for alarm signalling. If more than one signal is linked to one output the signals are OR linked. Each of the 3 limit values Lim.1 … Lim.3 has 2 trigger points H.x (Max) and L.x (Min), which can be switched off individually (parameter = “OFF”). Switching difference HYS.x and delay dEl.x of each limit value is adjustable.

Ü Operaing principle absolute alarm

L.1 = OFF

InL.1

H.1

HYS.1

InH.1

LED

H.1 = OFF

InL.1

L.1

HYS.1

LED

InH.1

* Operating principle relative alarm

L.1 = OFF

InL.1

H.1

HYS.1

H.1 = OFF

InL.1

L.1

HYS.1

LED

InH.1

LED

InH.1

L.1

InH.1

H.1

HYS.1

LED

InL.1

H.1

L.1

HYS.1 HYS.1

LED

InH.1

LED

InL.1

HYS.1

LED

1: normally closed ( ConF/ Out.x/O.Act=1 ) 2: normally open ( ConF/ Out.x/O.Act= 0 )

Alarm handling 26 8800 process controller

Operation

The variable to be monitored can be selected seperately for each alarm via configuration The following variables can be monitored:

process value

control deviation xw (process value - set-point)

control deviation xw + suppression after start-up or set-point change

After switching on or set-point changing, the alarm output is suppressed,

until the process value is within the limits for the first time. At the latest after expiration of time 10 ti1, the alarm is activated. (ti1 = integral time 1; parameter r Cntr)

If ti1 is switched off (ti1 = OFF), this is interpreted as Î, i.e. the alarm

is not activated, before the process value was within the limits once. Measured value INP1

Measured value INP2

Measured value INP3

effective set-point Weff

correcting variable y (controller output)

Deviation from SP internal

Process value - x2

If measured value monitoring + alarm status storage is chosen ( ConF / Lim / Fnc.x=2/4), the alarm relay remains switched on until the alarm is resetted in the error list ( Lim 1..3 = 1).

8800 process controller 27 Alarm handling

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West Control Solutions N8800 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual