Baelz Automatic mCelsitron 6490B Application guide

Page 1
Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
Microprocessor-based controller µCelsitron baelz 6490B,
baelz 6490B-y and baelz 6590B
Universal three-position step controller
Industrial controller with special PID step controller algorithm
 Compact design 96mm x 96mm x 135mm Compact design 48mm x 96mm x 140mm
 Easy operation
 User-defined operating level
 Digital displays for process variable and
setpoint
 Indication of the manipulated variable
(at 6490B-y with additional bargraph display)
 Control structure PI and PID
 Two-position control
 Three-position control
 Setpoint ramp
 Robust self-optimisation
 Measurement input Pt100
 Serial interface
 Alarm functions
 Control via digital inputs
 Manual/automatic switch over
 Degree of protection Front IP 65
 Semiconductor memory for data protection
 Plug-type terminals
 Rail-mounting (option)
Technical data subject to change without notice 052'+3/2nc E3By CW,Ro,Bö

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
Contents
1. Function overview .................................................................................................................................................................... 4
2. Operating and setting ................................................................................................................................................................ 5
2.1 Setting setpoint in automatic mode................................................................................................................................. 6
2.2 Opening/closing the actuator in manual mode................................................................................................................ 6
2.3 Modbus communication display via PV-display ............................................................................................................ 6
2.4 Displaying the manipulated variable Y via PV-display.................................................................................................. 6
2.5 Switch over to configuration level.................................................................................................................................. 7
2.6 Changing the scrolling direction in the configuration level............................................................................................ 8
2.7 Switch over to second operating level (user-defined operating level)............................................................................ 8
2.8 Setting configuration points............................................................................................................................................ 9
3. Configuration level ................................................................................................................................................................. 10
3.1 Optimisation for automatic determination of favourable control parameters.......................................... OPt.............. 10
3.2 Proportional band .................................................................................................................................... Pb................ 14
3.2.1 Three-position controller .............................................................................................................................................. 14
3.3 Integral action time.................................................................................................................................. tn................. 14
3.3.1 Two-position controller ................................................................................................................................................ 14
3.4 Derivative action time ............................................................................................................................. td................. 14
3.5 Dead band................................................................................................................................................ db................ 14
3.6 Actuating time ......................................................................................................................................... t.P................ 14
3.7 Basic alarm type description......................................................................................................................................... 15
3.7a Alarm type A ................................................................................................................................................................ 15
3.7b Alarm type B ................................................................................................................................................................ 15
3.7c Alarm type C ................................................................................................................................................................ 15
3.7.1 Alarm type selection for alarm relay ....................................................................................................... AL.1............ 16
3.8 Decimal point for LED displays.............................................................................................................. dP................ 17
3.9 Scaling the process variable display PV.................................................................................................. dI.L, dI.H .... 17
3.10 Setpoint limiting ...................................................................................................................................... SP.L, SP.H.. 17
3.11 *Second setpoint SP.2 at 6x90B(-y) /1 /4 /4-i....................................................................................... SP.2............. 17
3.12 Setpoint ramp SP.r................................................................................................................................... SP.r ............. 18
3.13 Ramp direction ........................................................................................................................................ rA.d............. 18
3.14 Delta setpoint........................................................................................................................................... dSP.............. 19
3.15 Delta setpoint description ............................................................................................................................................. 19
3.16 Process gain P.G...................................................................................................................................... P.G.............. 22
3.17 Measured value filter for the process variable PV................................................................................... FIL .............. 22
3.18 Behaviour in case of sensor failure for PV.............................................................................................. SE.b ............ 22
3.19 Interlocking the manual/automatic switch over....................................................................................... Man............. 22
3.20 Direction of effect of the controller......................................................................................................... dIr ............... 22
3.21 Assigning the control function SECOND SETPOINT SP.2 to a *digital input at 6x90B(-y) /1 /4 /4-i. S2.d............. 23
3.22 Assigning the control function OPEN to a *digital input at 6x90B(-y) /1 /4 /4-i.................................. OP.d............ 23
3.23 Assigning the control function CLOSE to a *digital input at 6x90B(-y) /1 /4 /4-i ............................... CL.d............ 23
3.24 Assigning the control function STOP to a *digital input at 6x90B(-y) /1 /4 /4-i .................................. St.d.............. 23
3.25 Important information about setting digital inputs ....................................................................................................... 23
3.26 Adjusting the digital inputs for the usage with INBAS ................................................................................................ 23
3.27 Calibration correction for the process variable input PV ........................................................................ C.CO........... 23
3.28 Synchronizing the manipulated variable Y-display................................................................................. Y.SY ........... 24
3.29 Important information about setting t.P in coherence with Y.SY at 6490B(-y) ......................................................... 25
3.30 Baud rate for *serial interface at 6x90B(-y) /3 /4 /4-i ............................................................................ bd................ 25
3.31 Address of *serial interface at 6x90B(-y) /3 /4 /4-i............................................................................... Adr.............. 25
3.32 *Serial communication at 6x90B(-y) /3 /4 /4-i...................................................................................... S.C .............. 25
3.33 Second operating level ............................................................................................................................ OL.2............ 25
3.34 Access to the configuration level............................................................................................................. PAS............. 25
* option

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
4. Mounting................................................................................................................................................................................. 26
5. Electrical connection............................................................................................................................................................... 26
5.1 Wiring diagram............................................................................................................................................................. 27
6. Commissioning ....................................................................................................................................................................... 28
7. Technical data......................................................................................................................................................................... 29
8. Ordering number baelz 6490B / 6490B-y / baelz 6590B........................................................................................................ 29
9. Overview of configuration level, data list............................................................................................................................... 31
Warning:
When operating electrical equipment, certain parts of this equipment automatically carry dangerous
voltages. Failure to observe these instructions could therefore lead to serious injury or material
damage. Therefore the warning notes, included in the following sections of these operating instruc-
tions, must be observed accordingly. Persons working with this unit must be properly qualified and
familiar with the contents of these operating instructions.
Perfect reliable operation of this unit presupposes suitable transport including proper storage,
installation and operation.

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
1. Function overview
Basic device
Analog input Pt100 Analog input for the process variable PV
Relay OPEN Controller output OPEN: opens the actuator
Relay CLOSE Controller output CLOSE: closes the actuator
Relay ALARM Alarm relay operates on the base of the idle current principle
Additional functions (option*)
Serial interface RS 485 Data transfer in accordance with modbus protocol.
Supply voltage 24 V DC For 24 V DC digital input and also 2-wire-transmitter at current input*
The optional digital input is definable to one of these functions by software:
Digital input OPEN Actuator opens ...
Digital input CLOSE Actuator closes ...
Digital input STOP Actuator persists in its current position ...
Digital input SP.2 To switch over to the second setpoint SP.2 ...
... if connecting 24 V DC (active state) to the appropriate digital input.
Priority: 1. STOP (highest priority), 2. CLOSE, 3. OPEN, 4. SP.2
Setpoint limiting. Minimum value SP.L (setpoint low), maximum value SP.H (setpoint high).
Only setpoints within the setpoint limiting can be set via front keyboard.
Setpoint ramp SP.r. Setpoint change per minute or hour (gradient). Can be specified for internal and external
setpoints by the setpoint ramp.
Filtering FIL of the process variable input PV. Interference signals and fast fluctuations of the process variable
PV can be smoothed by an adjustable software filter.
* Digital inputs, voltage range 0/12-24 V DC.
* Serial interface RS 485 (modbus, RTU-mode).
* option
}not in manual mode

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
2. Operating and setting
Operating level:
6490B
Actuator opens
Actuator closes
At the 6590B
symbols and
displays have the
same meaning.
Alarm
Process variable or manipulated
variable Y or modbus commu-
nication display
other phys. units available as
labels
Setpoint display with actual status
display for:
StOP = STOP DI active
CLOS = CLOSE DI active
OPEn = OPEN DI active
tunE = optimisation running
rAMP = Setpoint ramp running
SP_2 = Second setpoint active
If one of these functions is
active, the SP-display is
alternating between the status
display with the highest priority
and the setpoint. StOP has got
the highest priority and SP_2 the
lowest priority.
Operating level
6490B-y:
The 6490B-y is
equipped with an
additional bargraph
display on the right
hand side of the front-
plate, showing the
current manipulated
variable Y.
The bargraph can be
turned off by the
configuration point
Y.SY (see 3.28 Y.SY).
The bargraph displays the
manipulated variable Y in 10%
steps:
0% all bargraph LEDs off
>0% lowest LED on
≥10% following LED on
...
≥90% all LEDs on

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
2.1 Setting setpoint in automatic mode
Setting range: SP.L to SP.H
Fixed setpoint if S2.d is assigned to a digital input which is active (setpoint fixed to SP.2) or if S.C = 1 (settings via modbus,
only).
2.2 Opening/closing the actuator in manual mode
2.3 Modbus communication display via PV-display
To switch over to the modbus communication display, hold down the - key and the - key
simultaneously for at least 1 second until "c." is displayed in the left segment of the display. The
other 3 segments show the communication display as a 1-byte counter with a range of 0 to 255.
With each valid modbus package it counts up one unit. When the counter reaches 255 it wraps
around with the next modbus package and starts counting up from 0 again. If the display does not change the controller is not
addressed via modbus.
To return to the process variable display, hold down the - key and the - key simultaneously again until the process
variable is displayed.
2.4 Displaying the manipulated variable Y via PV-display
To switch over to the manipulated variable Y display, hold down the - key and the - key
simultaneously for at least 1 second until "Y." is displayed in the left segment of the display. The
other 3 segments show the manipulated variable Y as a numerical value (0...100) in percent.
To return to the process variable display, hold down the - key and the - key simultaneously
again until the process variable is displayed.
+>1s
+>1s

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
2.5 Switch over to configuration level

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
2.6 Changing the scrolling direction in the configuration level
In the second operating level as well as in the configuration level it is possible to inverse the scrolling direction.
The forward scrolling direction mode is automatically set with every power off-power on.
The selected scrolling mode is valid as long as it is not changed or until a power failure.
To switch to the reverse scrolling direction mode, hold down the - key and the - key
simultaneously until the previous configuration point is displayed.
Now scrolling inside the configuration level works in reverse mode.
To switch to the forward scrolling direction mode, hold down the - key and the - key
simultaneously until the next configuration point is displayed.
Now scrolling inside the configuration level works in forward mode.
2.7 Switch over to second operating level (user-defined operating level)
How to switch over from the operating level to the second operating level is described in the following diagram. Which
configuration point of the second operating level will be called up first depends on the selected scrolling mode x. Configuration
points that have been selected for the second operating level (see 3.33 OL.2) can be called up and adjusted without entering the
password. In case access to the configuration level is protected by a password, see 3.34 PAS.
* if this function has been selected for the user-defined operating level and the access to the configuration level has been
interlocked by the password.
xchanging the scrolling direction see 2.6.
For the second operating level the following settings can be adjusted:
- optimisation OPt - second setpoint SP.2
- alarm (i.e. A1.A, HY.1) - setpoint ramp SP.r
- serial communication S.C

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
2.8 Setting configuration points
1 Select configuration point
2a Set new value by change in individual steps and...
respectively
2b Set new value by continuous change
with increasing speed and...
3 ...confirm new value within 5s, otherwise the previous, still effective value
will be set again automatically.
4 After the new value has been confirmed by pressing , press again to
call up the next configuration point
Back to operating level, possible at any time

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3. Configuration level
For access to this level press >2s (see 2.5).
To switch to the next/previous configuration point (depending on the scrolling direction mode) press .
Inside the configuration level it is not possible to switch over to the manual mode.
3.1 Optimisation for automatic determination of favourable control parameters. OPt
Selection: 0 No optimisation
1 optimisation activated
Optimisation is triggered by:
• manual mode: switch over to automatic mode by pressing twice within two seconds
• automatic mode: changing the setpoint SP (not for external setpoint)
When tunE is shown cyclically in the setpoint display SP then the optimisation process is running.
optimisation from manual mode optimisation from automatic mode
Procedure of optimisation:
• Set target setpoint SP
• Switch to manual mode
• By opening/closing the actuator the actual value PV
is set on a higher/lower value than the
target setpoint (a)
• Wait until PV is in a stable state (b)
• Switch over to configuration level
• Set “OPt = 1”
• To optimise a PI-controller set derivation action time
“td = 0”; to optimise a PID-controller set “td ≠0”
• If known, set process gain “P.G”
(usual setting: P.G = 100%)
• Back to operating mode
• Switch over to automatic mode. Thereby optimisation is
• Set initial setpoint SP
• Wait until PV is in a stable state (b)
• Switch over to configuration level
• Set “OPt = 1”
• To optimise a PI-controller set derivation action time
“td = 0”; to optimise a PID-controller set “td ≠0”
• If known, set process gain “P.G”
(usual setting: P.G = 100%)
• Back to operating mode
• Set target setpoint SP. Thereby optimisation
is started, “tunE” and the manipulated variable appear
alternate, actuator changes
• During the optimisation process no inputs or
switch over are tolerated

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
started, “tunE” and the manipulated variable appear
alternate, actuator changes
• During the optimisation process no inputs or
switch over are tolerated
• Optimisation is finished as soon as “tunE” does not
appear anymore. Now the controller works in
automatic mode.
• The calculated parameters “Pb”, “tn”, “td” and also
the process gain “P.G“ have been calculated and
saved in the configuration level. “OPt = 0” is set
again automatically
• In case it was the first optimisation process, better
results are available by another optimisation run
(because of the process gain P.G, already calculated
during the first run)
• Optimisation is finished as soon as “tunE” does not
appear anymore. Now the controller works in
automatic mode.
• The calculated parameters “Pb”, “tn”, “td” and also
the process gain “P.G“ have been calculated and
saved in the configuration level. “OPt = 0” is set
again automatically
• In case it was the first optimisation process, better
results are available by another optimisation run
(because of the process gain P.G, already calculated
during the first run)
Problems with optimisation and solutions
1. Setting “OPt = 1” is not possible
Reasons:
a) Digital input (OPEN, CLOSE, STOP) is active.
Solution: Deactivate the digital input or take it out of the configuration level ( = 0).
b) Sensor does not work (display “Err”).
Solution: Make sure there is a valid actual value PV (check measuring lines and sensor).
2. Optimisation does not start (no alternating “tunE” and manipulated variable in the setpoint display SP)
By switching from manual to automatic mode or by changing the setpoint in the automatic mode, the optimisation is not started.
Reasons:
a) In the configuration level the “OPt” setting is not “1” (anymore). “OPt = 0” is set automatically in case of:
• optimisation is finished (no flashing „tunE“)
• digital input (OPEN, CLOSE, STOP) is still active or was active for a short moment
• sensor failure permanently or for a short moment in the past
Solution: Deactivate digital input (OPEN, CLOSE, STOP), remove sensor failure (see 1.a), 1.b)).
Set “OPt = 1”. Try again.
b) Digital input SP.2 is active. Optimisation with or on SP.2 is impossible.
Solution: Deactivate digital input or take it out of the configuration level ( = 0).
c) The control error between actual value and target setpoint is less than 3.125% of the entire measuring range.
I.e. a 0°C…300°C module is used the minimum control error has to be at least 9.4°C.
When a 0°C…400°C module is used it has to be at least 12.5°C.
Solution: Magnify the difference between actual value and target setpoint up to at least 3.125% of the measuring
range before starting the optimisation.
The bigger the deviations the better the optimisation results (see also 6.a), 6.b)).
When optimising from manual mode, the actuator has to be changed as long as the difference between
actual value and target setpoint is big enough.
When optimising from automatic mode, an initial setpoint, which has to have the necessary difference to
the target setpoint, has to be defined.
d) A modbus RAM-setpoint is used. Optimisation with or on the modbus RAM-setpoint is impossible.
Solution: Deactivate the RAM-setpoint via the modbus (see "Modbus documentation").

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3. Target setpoint is not reached during the optimisation
Immediately after the optimisation is finished ( “tunE” does not appear anymore) the actual value is not close to the
target setpoint. It is recommendable to reach the target setpoint as exactly as possible at the end of the optimisation to
get really good results.
Reasons:
a) The process gain P.G, defined before starting the optimisation, did not correspond to the actual process gain P.G of
the process. Frequently this happens during the first optimisation when the process gain P.G is still set to the standard
value = 100%.
Solution: Restart optimisation. The setpoint value will be reached more exactly this time, because the process gain P.G,
which was also calculated during the previous optimisation process, is used as a base of the following
optimisation process. If the process gain is known or measured, it can be adjusted manually already before
starting the first optimisation run.
Measuring the process gain P.G in manual mode:
Change the actuator about a fixed rate ∆Y (%) and determine the given change of the actual value ∆PV.
Then the process gain can be calculated by P.G = (∆PV / ∆Y) * 100%. If the controlled system has got a
linear behaviour, the process gain is constant all over the entire control range.
I.e. the actuator is changed from 30% to 70% →∆Y = 40%. Thereby the actual value rises from
50°C to 110°C →∆T = 60°C. At a measuring range of 0°C…300°C this corresponds to the change of the
actual value ∆PV = 20%. The process gain can be calculated then by P.G = (20% / 40%) * 100% = 50%.
Depending on the process gain, the controller calculates the necessary change of the actuator at start of the
optimisation for reaching the target setpoint at the end of the optimisation.
A small process gains causes a bigger change of the actuator instead of a bigger process gain.
If the temperature rises up to a not permitted high value, it could be necessary to cancel the optimisation
(see also 5.).
b) In non-linear controlled systems, even by proceeding a following optimisation, the target setpoint can not be reached
exactly enough.
Solution: Let the optimisation run a couple times until the target setpoint is reached exactly enough. The process gain will
be defined then by an iterative method, what means, with every run the process gain comes closer to the actual
process gain.
In non-linear controlled systems for different sub-ranges within there will be optimised, different optimisation
results will be created. Therefore it is necessary to determine the most important range for the control which
should be optimised. If all ranges do have the same importance, we recommend you to optimise the sub-range
with the slowest time behaviour (see also 6.a) and 6.b)).
c) The prime energy is not sufficient to reach the target setpoint.
Solution: Increase prime energy or chose a target setpoint that can definitely be reached.
d) The actuator does not move to the new position given by the controller.
Solution: Check function of the actuator and its control.
4. The optimisation “does not” finish or just after 42 minutes respectively
The maximum time of optimisation is limited up to 42 minutes. In case that the conditions to finish the optimisation are not
given even after 42 minutes, the optimisation process will be cancelled automatically.
Reasons:
a) The limited time of 42 minutes for optimisation might be too short for several, very slow processes.
Solution: Switch over to the configuration level just before the 42 minutes are elapsed and change the setting “OPt = 1”
to “OPt = 0”. Therefore the optimisation is cancelled manually and the control parameters will be recalculated.
b) At processes with no stable state (drift, post heating, ...) cancelling the optimisation after 42 minutes is possible just as a
later ending.
Solution: The movement of the actual value has to be observed to recognize the approximate end of the settling.
Afterwards in the configuration level the setting “OPt = 1” has to be changed to “OPt = 0” to cancel the
optimisation with recalculation of the control parameters.
If there is a drift, the optimisation has to be started from the manual mode before the drift starts.
c) Because of the change of the manipulated variable at start of the optimisation, the change of the actual value ∆PV is
too small, so the balance of the controlled system is not recognized.
The change of the actual value ∆PV has to be at least 1/4 of the difference between target setpoint and actual value at
beginning of the optimisation.

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
I.e. actual value at start of the optimisation = 60°C, target setpoint = 100°C which is a difference of ∆T = 40°C.
The needful change of the actual value can be calculated then by ∆PV = 1/4 * ∆T = 1/4 *40K = 10K.
The optimisation can only be finished when the actual value is at least 60°C + 10K = 70°C.
Cause is a process gain which does not fit (see also 3.a) and 3.b)).
Solution: Cancel or finish the optimisation (see 5.).
Reduce the process gain P.G in the configuration level (e.g. 1/2).
Restart optimisation.
5. Cancelling the optimisation premature
An already running optimisation shall be cancelled without recalculation of the control parameters.
A reason for that could be e.g. a not permitted rise of the temperature over the tolerated limits during the optimisation.
After a cancel the process gain P.G can be magnified manually to get a smoother temperature change within the next
optimisation (see also 3.a) and 3.b)).
Cancelling by:
a) activating manual mode
b) setting a setpoint once more
c) activating a digital input (OPEN, CLOSE, STOP, SP.2)
d) activating the modbus RAM-setpoint (see "Modbus documentation")
Cancelling the optimisation premature, including recalculation of control parameters and process gain, can be realized by
changing "Opt = 1" to "Opt = 0" in the configuration level during process of optimisation.
6. The optimisation results are not satisfying
Reasons:
a) The optimisation did not run within the range the control is working after.
I.e. the range between 60°C and 80°C was optimised, but the following control works with a setpoint change
from 50°C to 100°C.
Solution: At beginning of the optimisation the actual value should correspond to the first point and the initial setpoint
to the other (target setpoint) of the desired control range (see also 2.c)).
b) Processes with strongly different time behaviour (e.g. fast heating up, slow cooling down) where the change of the
actual value during the optimisation worked reverse to the following control.
I.e. optimisation from 100°C to 50°C but the following control from 50°C to 100°C.
Solution: If possible, optimise in the same direction the control is working after. If it has to be controlled in both
directions, the more important direction has to be optimised. Do both directions have the same relevance,
the slower process has to be optimised.
c) The actual value has not been in a stable state before starting the optimisation.
Solution: Wait until the actual value is in a stable state before starting the optimisation. If the actual value can not get
stabilized in the automatic mode (oscillation), an optimisation started from the manual mode is necessary.
d) The target setpoint could not be reached at the end of the optimisation.
Solution: see 3)
e) During the optimisation the actuator must not run over the limits →neither 0% nor 100%. Nevertheless a completely closed
actuator at start of the optimisation would be tolerated, i.e. in case that a de-energized plant (with closed actuator) drives
immediately to the target setpoint at start of the optimisation.
Solution: Set a bigger process gain and restart optimisation or just set another target setpoint.
f) Power supply is not stable because of too many peripherals.
Solution: Optimisation only at times when a stable energy supply is guaranteed.
g) Controlling the process is almost impossible because the actuator does not fit (e.g. valve is over-sized).
Solution: Check dimensions of the actuator, change it if necessary.
h) The process can not be controlled perfectly with the chosen type of controller.
Solution: Let the optimisation run with another type of controller (PI or PID) and compare.

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.2 Proportional band Pb
Setting range: 1.0% to 999.9%
Proportional action of the PI(D) three-position step controller
3.2.1 Three-position controller
Pb = 0.0
tn > 0
Control action adjustable via dead band db
(see also 3.5 db)
3.3 Integral action time tn
Setting range: 1s to 2600s
Integral action of the PI(D) three-position
step controller
3.3.1 Two-position controller
tn = 0
Control action adjustable via dead band db
(see also 3.5 db)
3.4 Derivative action time td
Derivative action of the PID three-position step controller
Setting range: 1s to 255s
3.5 Dead band db
No actuating pulses if control deviation is smaller than db
Hysteresis: db/2
Setting range:
0 to 10th part of the scope of the measuring range
[phys. units]
0 to + scope of the measuring range [phys. units] at dP = 3
(see also 3.2.1 three-position controller
3.3.1 two-position controller)
3.6 Actuating time t.P
(Valve actuation time)
Setting range: 5s to 300s
Time to pass through the setting range 0% to 100% (stroke) at constant OPEN or CLOSE pulse
Setting the valve actuating time t.P has got a very important meaning. It has to be ascertained as
exact as possible for each valve and set to the controller. A bad valve actuating time causes a wrong
manipulated variable.
3.2.1 Three-position controller
3.3.1 Two-position controller
3.5 Dead band

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.7 Basic alarm type description
The controller has got three basic types of alarms called type A, type B and type C.
3.7a Alarm type A
Alarm at a limit value based on the setpoint SP.
Alarm at over-temperature if alarm setting A1.A is
positive. Alarm at under-temperature if alarm setting
A1.A is negative. At positive setting the alarm is
triggered if PV is bigger than SP + A1.A . At
negative setting the alarm is triggered if PV is smaller
than SP -A1.A. The algebraic sign of the alarm
value A1.A only indicates the direction of effect
(over- or under-temperature).
The hysteresis defines a span between alarm state and
switching back to normal state. At positive setting of
A1.A returning to normal state is at
SP + A1.A - HY.1 . At negative setting of A1.A
returning to normal state is at SP - A1.A+ HY.1 .
Alarm type A
3.7b Alarm type B
Alarm at a fixed limit value of PV.
If AL.1 = 2, alarm is triggered if the value set at
A1.b is reached or exceeded.
The hysteresis defines a span between alarm state
and switching back to normal state. Returning to
normal state is at A1.b - HY.1 .
If AL.1 = 4, alarm is triggered if the value set at
A1.b is reached or dropped below.
The hysteresis defines a span between alarm state
and switching back to normal state. Returning to
normal state is at A1.b + HY.1 .
Alarm type B
3.7c Alarm type C
Alarm at leaving a band around the setpoint SP.
The lower half of the band is defined by A1.C ,
the higher one by A1.C. .
The value entered at A1.C is always negative
because the process variable PV has to be
smaller than SP -A1.Cto trigger the alarm.
The value entered at A1.C. is always positive
because the process variable PV has to be
bigger than SP + A1.C. to trigger the alarm.
The hysteresis defines a span between alarm
state and switching back to normal state. For the
lower band returning to normal state is at
SP -A1.C+ HY.1 . For the higher band
returning to normal state is at
SP + A1.C. - HY.1. .
Alarm type C
At all three types (A, B, C) alarm is always triggered in case of sensor failure.

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.7.1 Alarm type selection for alarm relay AL.1
The alarm relay operates on the base of the idle current principle.
AL.1 = 0: no alarm selected
also not in case of sensor failure, see also 3.18 SE.b
AL.1 = 1: selects Al.A alarm type A (see description 3.7a)
Setting range: 0 to ± scope of the measuring range [phys. units]
Alarm hysteresis HY.1 for A1.A
Setting range: 0 to 10th part of the scope of the measuring range [phys. units]
0 to + scope of the measuring range [phys. units] at dP = 3
AL.1 = 2: selects Al.b alarm type B (see description 3.7b)
Setting range: measuring range [phys. units]
Alarm hysteresis HY.1 for A1.b
Setting range: 0 to 10th part of the scope of the measuring range [phys. units]
0 to + scope of the measuring range [phys. units] at dP = 3
AL.1 = 3: selects Al.C and Al.C. alarm type C (see description 3.7c)
Lower half of the band around the setpoint (negative setting)
Setting range: 0 to - scope of the measuring range [phys. units]
Alarm hysteresis HY.1 for A1.C
Setting range: 0 to 10th part of the scope of the measuring range [phys. units]
0 to + scope of the measuring range [phys. units] at dP = 3
Upper half of the band around the setpoint (positive setting)
Setting range: 0 to + scope of the measuring range [phys. units]
Alarm hysteresis HY.1. for A1.C.
Setting range: 0 to 10th part of the scope of the measuring range [phys. units]
0 to + scope of the measuring range [phys. units]at dP = 3
AL.1 = 4: selects A1.b alarm type B, version 2 (see description 3.7b)
Setting range: measuring range [phys. units]
Alarm hysteresis HY.1 for A1.b
Setting range: 0 to 10th part of the scope of the measuring range [phys. units]
0 to + scope of the measuring range [phys. units] at dP = 3

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.8 Decimal point for LED displays dP
Selection: 0 Display without decimal point: #### 2 Display with 2 decimals: ##.##
1 Display with decimal point (1 decimal): ###.# 3 Display with 3 decimals: #.###
After any change of the decimal point the process variable display PV has to be rescaled (see 3.9 dI.L, dI.H).
By changing the decimal point, several other inputs of the configuration level are concerned. Because of the
high degree of accuracy of some inputs approximation errors may be possible.
3.9 Scaling the process variable display PV dI.L, dI.H
Display low: enter zero point of the measuring range.
Defines the starting point for the PV indication related to the measuring range whereat dI.L < dI.H.
Setting range (depending on dP): -999 ... 9999 [phys. units] at dP = 0
-0.999 ... 9.999 [phys. units] at dP = 3. See also 3.8 dP.
Standard value: 0°C and 32°F respectively
Display high: enter final point of the measuring range.
Defines the final point for the PV indication related to the measuring range whereat dI.H > dI.L
Setting range (depending on dP): -999 ... 9999 [phys. units] at dP = 0
-0.999 ... 9.999 [phys. units] at dP = 3. See also 3.8 dP.
Standard value: 300°C and 572°F respectively
- When changing dI.L or dI.H, all values entered as physical units are rescaled expressed as
percentage
- When a Pt100 sensor is used, dI.L and dI.H have to correspond to the Pt100 measuring range of the
device (see type plate)
baelz 6490B / 6490B-y / 6590B - 2.4 - ... : dI.L = 0, dI.H = 300
baelz 6490B / 6490B-y / 6590B - 2.2 - ... : dI.L = 0, dI.H = 400
3.10 Setpoint limiting SP.L, SP.H
Setpoint low: lowest setpoint which can be set
Setting range: dI.L to SP.H [phys. units] (see also 3.9 dI.L)
Effective for the setpoint adjustable via front keyboard.
Setpoint high: highest setpoint which can be set
Setting range: SP.L to dI.H [phys. units] (see also 3.9 dI.H)
Effective for the setpoint adjustable via front keyboard.
- If the range of dI.L/dI.H is changed, SP.L/SP.H is automatically set according to it expressed as
percentage.
- When SP.L = SP.H, the setpoint is fixed to this value. Changing the setpoint is not possible.
- When SP.L > SP.H, only between these two values can be switched via front keyboard. After
setting SP.L > SP.H, the last entered setpoint is displayed in the operating level.
The two fixed setpoints can be selected by pressing or and adjusted by pressing .
3.11 *Second setpoint SP.2 at 6x90B(-y) /1 /4 /4-i SP.2
Setting range: dI.L to dI.H [phys. units] (see also 3.9 dI.L, dI.H)
When the digital input assigned to SP.2 is active, the corresponding value becomes the actual setpoint
(see also 3.21-3.25 Assigning the digital inputs).
* option

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.12 Setpoint ramp SP.r SP.r
Defines the ramp of the setpoint SP via time (gradient)
Setting range:0 to scope of the measuring range in
PV/minutes or hours
(see below 3.13 rA.d); PV [phys. unit]
e.g. K/min or hour (at dP = 0)
Setting SP.r = 0: no setpoint ramp.
Start value of the setpoint ramp is always the current
value of the process variable PV (a).
The current setpoint is displayed.
3.12 Setpoint ramp SP.r
The setpoint ramp is triggered after:
- switching on the device or after a power failure
- sensor failure
- any setpoint change
- switching over to the second setpoint SP.2
- a control function STOP, CLOSE, OPEN (via digital input)
- switching from manual mode to automatic mode
3.13 Ramp direction rA.d
Setting the direction of effect and time behaviour of the setpoint ramp SP.r (if SP.r > 0, see also 3.12 SP.r)
Selection: 0 Ramp with SP.r as *physical unit/min, at falling and rising setpoint changes.
1 Ramp with SP.r as *physical unit/min, only at rising setpoint changes.
2 Ramp with SP.r as *physical unit/min, only at falling setpoint changes.
3 Ramp is deactivated (similar to setting SP.r = 0 ).
4 Ramp with SP.r as *physical unit/hour, at falling and rising setpoint changes.
5 Ramp with SP.r as *physical unit/hour, only at rising setpoint changes.
6 Ramp with SP.r as *physical unit/hour, only at falling setpoint changes.
* physical unit see 3.9 adjusting dI.L, dI.H

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.14 Delta setpoint dSP
Setting range: 0 to ± scope of measuring range [phys. units]
dSP = 0 No delta setpoint.
dSP ≠0 As soon as the STOP command is deactivated by an assigned digital input the setpoint will be
changed by the value [phys. unit] set in dSP.
Assigning the control function STOP to a digital input, see 3.24.
3.15 Delta setpoint description
3.15.1 Remarks concerning the start up behaviour of tenters
Improving the start up behaviour by using the delta setpoint dSP and/or a setpoint ramp SP.r.
3.15.2 Start up behaviour without delta setpoint or setpoint ramp
Fig. 1)
After the plant has been switched off, the temperature in the tenter has to drop below the hysteresis of the alarm
relay until the control of the burner is released again (1).
Then the burner can be moved to its ignition position and be started. As soon as the STOP command is inactive
the controller switches to the automatic mode (2).
Problem: As a result of the given ignition position of the mixer, during the ignition phase of the burner the
thermal energy put into the plant is considerable. However, this does not immediately result in a measurable rise
of temperature due to the time delay of the plant.
As soon as the STOP command is inactive the controller immediately generates a longer OPEN pulse because
of the under-temperature Xw.
The addition of these processes (quantity of heat of the ignition + quantity of heat of the first OPEN pulse)
results in a temperature overshoot which, in turn, can trigger the alarm relay (3).
This causes switching off the plant and a restart of the procedure.

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Device manual 6490B / 6490B-y / 6590B
W. Bälz & Sohn GmbH & Co. Koepffstraße 5 D-74076 Heilbronn Telefon [phone] Telefax (07131) 1500-21
3.15.3 Start up behaviour with delta setpoint dSP
Fig. 2)
Because of the delta setpoint, as soon as the STOP command is inactive, the first OPEN pulse is either
shortened according to the adjusted setpoint lowering and the control deviation Xw, or a CLOSE pulse may
even be given (2).
Example: There is a control deviation of Xw = 15 K. The delta setpoint dSP is adjusted to a setpoint lowering
of -10 K.
As soon as the STOP command is inactive the controller generates only an OPEN pulse according to the
under-temperature of 5 K, instead of an OPEN pulse according to an under-temperature of 15 K.
Example: There is a control deviation of Xw = 10 K. The delta setpoint dSP is adjusted to a setpoint lowering
of -15 K.
As soon as the STOP command is inactive the controller generates a CLOSE pulse according to the
over-temperature of 5 K, instead of an OPEN pulse according to an under-temperature of 10 K.
Because of the high energy input during the ignition stage the temperature can still rise after a possible
CLOSE pulse.
Temperature overshoot is limited by delta setpoint (3). However, its effectiveness depends on the correct
dSP setting like shown in the examples.