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KEB COMBIVERT F5-A,-E,-H 4.0. APPLICATION MANUAL (2008) - page 8

Setpoint-, Rotation- and Ramp Adjustment

Example 2

Relative value (oP.64):

2000 rpm

Desired setpoint:

32,37843 rpm

32,37843 rpm

oP.63 =

———————

x 2³⁰ = 17383037

2000 rpm

Resolution and scaling factor are the same as for oP.63. Due to internal rounding, the value of ru.82 may be 1

less than the set value oP.63.

7.4.3

Rotation source oP.01

The selection of rotation direction determines the manner in which the rotation direction is adjusted. One can

choose between following possibilities:

Figure 7.4.3 Rotation selection with oP.01

digital

Terminal strip

Terminal strip

Setpoint

Control word

Setpoint depen-

oP.02

forward/reverse

Run / Stop

dependent

SY.50

dent

Control word

0-lim.

abs.

0-lim.

abs.

0-lim.

abs.

LS

no LS

0-lim.

abs.

Run / Stop

7

4

5

3

6

2

7

1

8

0

9

oP. 1

10

0-limited or absolute

Concerning the adjustment of direction of rotation it is differentiated between two evaluations:

0 limited:

negative setpoints are set to zero, i.e. only positive setpoints are driven in accordance with the selected rotation

direction

Page7.4 - 7

Setpoint-, Rotation- and Ramp Adjustment

absolute:

no sign of the set value is evaluated and it is always driven with the amount in accordance with the selected

rotation direction

Figure 7.4.3.a Absolute and 0 limited set value setting

0-limited

absolute

Setpoint

Setpoint

Setpoint

Setpoint

adjust-

adjust-

ment

ment

Rotation setting oP.02 ; (oP.01 = 0 or 1)

oP.02: Rotation setting

Bit

Display

Setpoint rotation

0

LS

Standstill (Low Speed)

1

F

forward (clockwise rotation)

2

R

reverse (counter-clockwise rota-

tion)

Rotation adjustment via terminal strip

The rotation selection via terminal strip allows the adjustment of the direction of rotation via switch or from a

primary control.

Direction forward input selection (Run / Stop) oP.60, direction reverse (forward / reverse) oP.61

With parameter oP.60 one input is determined for rotation direction forward (or run/stop) and with oP.61 one

input for rotation direction reverse (respectively forward/reverse). (see chapter 7.3)

Page7.4 - 8

Setpoint-, Rotation- and Ramp Adjustment

oP.01 = "2" or "3"

In case of rotation selection forward/reverse (oP.01= "2" or "3") the inputs determined with oP.60 and oP.61

work as follows:

Forward

Reverse

Input

X2A.14

X2A.15

F

R

Function

0

0

LS

0

1

counter-

clockwise

rotation

1

0

clockwise

rotation

1

1

clockwise

rotation

oP.1 = "4" or "5"

In the case of rotation selection run/stop and forward/reverse (oP.01= "4" or "5") the inputs determined with

oP.60 and oP.61 work as follows:

forward

reverse

Input

X2A.14

X2A.15

F

R

Function

0

0

LS

0

1

LS

7

1

0

clockwise

rotation

1

1

counter-

clockwise

rotation

Rotation direction is dependent on the sign of the setpoint

The direction of rotation can be defined with the preadjusted set value signal. In the case of analog signals

through adjustment of positive or negative voltages. In the case of digital signals through adjustment of positive

values (without sign) or negative values (negative sign in the display).

Following adjustments are possible:

Evaluation with LS (Switch off the modulation) (oP.01 = 6 or 10)

In this case "F" or "R" must be set via a digital input, digital via oP.2 or "start" via control word SY.50 in order for

the inverter to modulate. It is unimportant which rotation setting is used, as the direction of rotation is dependent

on the setpoint.

Page7.4 - 9

Setpoint-, Rotation- and Ramp Adjustment

oP.01 = 10: The rotation direction release is done exclusively via the control word Run/Stop.

No rotation direction set

-> LS (Modulation disabled)

A direction of rotation is set and oP.01 = 6 or 10

-> Clockwise direction of rotation

negative value

-> Anti-clockwise direction of rotation

Evaluation without LS (oP.01 = 7)

In this case the inverter always modulates.No direction of rotation needs to be adjusted.

oP.01 = 7:

pos. value (also 0)

-> Clockwise direction of rota-

tion

negative value

-> Anti-clockwise direction of

rotation

Rotation direction dependent on the control word SY.50

The control word is used for the state control of the inverter via bus. In order for the inverter to react to the con-

trol word, the respective control process must be enabled (oP.01=8 or 9; fr.02 = 5). When adjusting the direction

of rotation via the control word, the setpoint can be evaluated 0-limited (oP.01 = 8) or absolute (oP.01 = 9).

Control word Sy.50

Bit

Function

Description

0 = Setpoint rotation Stop; 1 = Rotation direction Run

2

Run / Stop

(source of set value direction op.1 = 6, 8, 9 or 10)

0 = Setpoint rotation forward; 1 = Rotation direction counter-clockwise

3

For / Rev

(source of set value direction op.1 = 6, 8, 9 or 10)

If Run/Stop is to be adjusted over the control word, oP.02 must be set to "0". The

terminals F/R may not be wired (OR-operation of terminal, oP.02 and Sy.50).

Page7.4 - 10

Setpoint-, Rotation- and Ramp Adjustment

7.4.4

Fixed frequencies (oP.18...23)

The KEB COMBIVERT supports up to 3 fixed frequencies for each parameter set, which can be selected via

two digital inputs. With oP.19 and oP.20 the inputs required for the selection are defined (also see "Digital in-

puts" Chapt. 7.3.11). The rotation direction source for fixed value mode is defined with oP.18. The adjustment

is independent of oP.01 and is valid exclusively for the fixed frequencies. The adjustment of a fixed frequency

has priority over the "normal" setpoint adjustment.

Figure 7.4.4 Fixed values

digital

Terminal strip

Terminal strip

Setpoint

DRIVECOM

oP.2

For / Rev

Run / Stop

dependent

SY.50

Input

Input

0-lim. abs.

0-lim. abs.

0-lim. abs.

LS

no LS

0-lim.

abs.

fixed frequency 1

fixed frequency 2

4

5

3

6

oP.19 Step value input

oP.20 Step value input

2

7

selection 1

selection 2

1

8

0...4095

0...4095

(according to table)

(according to table)

0

9

oP. 18

Fixed value

Rotation direction source

Fixed frequency 1

Fixed frequency 2

oP.21:

oP.22:

-4000...4000 rpm

-4000...4000 rpm

7

Fixed frequency 3

oP.23: -4000...4000 rpm

Setpoint limits

Selection of fixed values

Figure 7.4.4.a Selection of fixed values

Input fixed value 1

Input fixed value 2

Setpoint

f3

f2

Fixed value f1...f3

f1

t

Page7.4 - 11

Setpoint-, Rotation- and Ramp Adjustment

Step value rotation source (oP.18)

With oP.18 it is defined how the direction of rotation is determined in case of active fixed value.The function and

the value range correspond to oP.1.

oP.18: Step value rotation source

Value

Function

0

Digital via oP.2; setpoint 0-limited

1

Digital via oP.2; setpoint absolute

2

Terminal strip F/R; setpoint 0-limited

3

Terminal strip F/R; setpoint absolute

4

Terminal strip Run/Stop; setpoint 0-limited

5

Terminal strip Run/Stop; setpoint absolute

6

Setpoint-dependent with LS-recognition

7

Setpoint-dependent without LS-recognition

8

Control word SY.50; 0-limited

9

Control word SY.50; 0-absolute

10

Setpoint + control word(SY.50) R/S

Step value input selection 1 and 2 (oP.19; oP.20)

See chapter 7.3.1 "digital inputs".

Step value 1...3 (oP.21, oP.22, oP.23)

The three step values oP.21...23 are set-programmable and can be adjusted in the range of -4000...4000 rpm.

Page7.4 - 12

Setpoint-, Rotation- and Ramp Adjustment

7.4.5

Setpoint limits

Following limit values can be preadjusted:

Figure 7.4.5 Setpoint limits

+n [rpm]

4000

Absolute maximal setpoint

oP.14

forward

oP.10

Maximal frequency for-

ward

-100

oP.6

Minimal frequency for-

oP.7*¹ (oP.6)

+100

ward

Setpoint [%]

Setpoint [%]

Minimal frequency reverse

oP.11*¹ (oP.10)

oP.15*¹ (oP.14)

Maximal value reverse

-4000

Absolute maximal frequency

reverse

7

-n [rpm]

*1 If the value "=For" is adjusted in these parameters (limit values rotation direction reverse), then the adjusted

values for rotation direction forward (oP.6, oP.10 and oP.14) are valid.

Min./ max. setpoints (oP.6, oP.7, oP.10, oP.11)

In case of analog and percentaged setpoint adjustment in percent the minimal and maximal frequencies form

the characteristic for the frequency calculation (0% = minimal frequency; 100% = maximal frequency). In case

of digital setpoint adjustment or fixed value the minimal and maximal frequencies limit the setpoint. Separate

limits can be adjusted for both rotation directions. If the value "For" is adjusted for rotation direction "Reverse",

then the values for "Forward" are valid.

Setting range:

oP.6: 0...4000 rpm

Default: 0 rpm

oP.10: 0...4000 rpm

Default: 2100 rpm

oP.7: =For, 0...4000 rpm

Default: =For

oP.11: =For, 0...4000 rpm

Default: =For

Absolute maximum setpoints (oP.14, oP.15)

After the minimal and maximal frequencies the setpoint is limited through the absolute maximal frequency and

subsequently transferred to the ramp generator. Since the analog setpoint is always calculated onto the maxi-

mal frequencies (oP.10, oP.11), it is possible, to adjust the characteristic of the analog setpoint with the same

gain for both rotation directions (see Fig.7.4.5.a) in spite of different maximal output frequencies. If the value

Page7.4 - 13

Setpoint-, Rotation- and Ramp Adjustment

"For" is adjusted in oP.15, then the absolute maximal speed of oP.14 is valid for both directions of rotation.

Max. output value forward (oP.40) / Max. output value reverse (oP.41)

All other limits (oP.10 / oP.11 "max. reference" and oP.14 / oP.15 "abs. max. reference") limit the speed setpoint

exclusively.

This function is active only if the alarm for the utilised encoder channel is activated (alarm

= on) in parameter Ec.42 "encoder alarm mode". In vector-controlled operation without

speed feedback, speed limiting is always active.

The status "58: ERROR!speed limit exceeded" (E.OS) is triggered if ru.07 "actual value display" exceeds either

oP.40 / oP.41 "output frequency limit" or ru.79 "abs. speed value EMK" (only for synchronous motors).

With oP.40 / oP.41, the user sets limits that may not be exceeded by the application under any circumstances.

ru.79 shows the maximum speed for a synchronous motor which, if exceeded, leads to an EMK of the motor

high enough to damage the DC-intermediate circuit of the inverter.

Reason for the occurence of excessive speed can be too small a distance between the maximum setpoint and

the speed limit, so that overshoots can trigger the error. Other causes can be (e.g., caused by EMK) malfunc-

tions in the speed measurement or a noisy, insufficiently smoothed speed estimate in the encoderless control

(SCL or ASCL).

Fig. 7.4.5.a

Setpoint limits

+n [rpm]

(oP. 10)

Absolute maximal va-

lue forward

(oP.14)

Maximal frequency

forward

Setpoint [%]

Setpoint [%]

-100%

+100%

Maximal frequency

(oP.11)

reverse

-n [rpm]

Page7.4 - 14

Setpoint-, Rotation- and Ramp Adjustment

7.4.7

Ramp generator

The ramp generator assigns an adjustable time to a speed change, during this time the change stall take

place. The acceleration time (for pos. speed changes) and deceleration time (for neg. speed changes) can be

adjusted separately for both directions of rotation. To enable jerk-free acceleration and deceleration, so-called

S-curves can be adjusted in addition to it.

The ramp times refer to 1000 rpm (at ud.02 = 4), or to 2000 rpm (at ud.02 = 8) and change in proportion to the

mode. The times to be adjusted are calculated as follows:

desired ramp time

Speed change (∆n)

-----------------------------------

=

----------------——----

ramp time to be adjusted (oP.28...oP.31)

1000 rpm (dep.on ud.02)

Fig. 7.4.7

Acceleration and deceleration times

+n [rpm]

1000

500

oP.29 ^*1

oP.31 ^*1

∆ n

∆n

∆ t

∆ t

∆ t

∆ t

0

oP.28

oP.30

∆ n

∆ n

800

1000

-n [rpm]

oP.28

Acceleration time forward

If the value "=For" is adjusted in these parameters (accelerati-

on and deceleration times for rotation direction reverse), then

oP.29

^*1

Acceleration time reverse

*1

the values of rotation direction forward (oP.28 and oP.30) are

oP.30

^*2

Deceleration time forward

valid.

oP.31

^*1

Deceleration time reverse

∆ n

speed change

*2

If the value "=Acc" is adjusted, then the value of acceleration

forward (oP.28) is valid.

∆ t

Acceleration time for ∆n

Page7.4 - 16

Setpoint-, Rotation- and Ramp Adjustment

Acceleration/deceleration time factor (oP.62)

The time factor extends the standard ramp time (oP.28...31) by the adjusted value. The S-curve time do not

change.

Value

Ramp time

0

Adjusted value x 1

1

Adjusted value x 2

2

Adjusted value x 4

3

Adjusted value x 8

4

Adjusted value x 16

Calculation of the acceleration and deceleration times

1000 rpm x real ramp time

oP.28...oP.31 =

——————————————

∆n

Example

A drive should accelerate from 100 rpm to 1000 ^{rpm in} 5 s.

5s x 1000 rpm

oP.28 =

———————--------

= 5,5 s

1000 rpm - 100 rpm

7

S-curve time

For some applications it is of advantage when the drive starts and stops jerk-free. This is achieved through a

straightening of the acceleration and deceleration ramps. The straightening time, also called S-curve time, can

be preadjusted with the parameters oP.32...oP.35. But S-curves are executed only with the adjustment oP.27

"Ramp with constant rise".

Page7.4 - 17

Setpoint-, Rotation- and Ramp Adjustment

Figure 7.4.7.a S-curve time

+n [rpm]

1000

oP.29

oP.31

oP.33

oP.33

oP.35

oP.35

t [s]

0

oP.32

oP.32

oP.34

oP.34

oP.28

oP.30

-1000

-n [rpm]

oP.28

Acceleration time forward

If the value "For" is adjusted in these parameters (for ro-

*1

tation direction reverse), then the values adjusted in the

oP.29

Acceleration time reverse

*1

parameters for rotation direction forward are valid.

*2

oP.30

Deceleration time forward

oP.31

*1

Deceleration time reverse

If the value "=Acc" is adjusted, then the value for acce-

*2

leration forward (oP.28) is valid.

oP.32

S-curve time acceleration forward

*1

oP.33

S-curve time acceleration reverse

If the value "=Acc" is adjusted, then the value adjusted

3

in parameter oP.32 is valid for all S-curve times. Value

oP.34

S-curve time deceleration forward

*3

"0" switches the corresponding S-curve off.

*1

oP.35

S-curve time deceleration reverse

In order to drive defined ramps with activated S-curve time, the preadjusted acceleration and deceleration times

(oP.28...oP.31) must be larger than the S-curve time (oP.32...oP.34) belonging to it.

Example for acceleration with rotation direction forward

At the beginning and the end of the acceleration ramp a parabolic curve is driven for the time adjusted in para-

meter oP.32. If the S-curves are traversed completely, the set ramp time is increased by oP.32.

Upper S-curve times (op.70...op.73)

Page7.4 - 18

Setpoint-, Rotation- and Ramp Adjustment

Parameters oP.70...oP.73 adjust the upper S-curves. If the value is -1 (default setting), the parameters oP.32...

oP.35 apply for the upper and lower S-curves (see figure 7.4.7.a).

Parameter

Name

Va-

Meaning

lue

Lower S-curve

Lower S-curve time acc.

also applies to the upper S-curve if oP.70 = -1

oP.32

forward

0

off

also applies to the upper S-curve if oP.71 = -1

Lower S-curve time acc.

oP.33

0

off

reverse

-1

= op.32

also applies to the upper S-curve if oP.72 = -1

Lower S-curve time dec.

oP.34

0

off

forward

-1

= op.32

also applies to the upper S-curve if oP.73 = -1

Lower S-curve time dec.

oP.35

0

off

reverse

-1

= op.34

upper S-curve

Upper S-curve time acc.

0

off

oP.70

forward

-1

= op.32 (default)

0

off

Upper S-curve time acc.

oP.71

-1

= op.33 (default)

reverse

-2

= op.70

0

off

7

Upper S-curve time dec.

oP.72

-1

= op.34 (default)

forward

-2

= op.70

Upper S-curve time dec.

0

off

oP.73

reverse

-1

= op.35 (default)

Page7.4 - 19

Setpoint-, Rotation- and Ramp Adjustment

7.4.8

acc dec mode

7.4.8.1Ramp with constant ascent

The different ramp functions can be adjusted separately for every frequency change (acceleration forward,

deceleration forward and so on). The selection is made with oP.27 and is adjustable separately in each set. The

function is activated after pressing "ENTER".

oP.27: Acc dec mode

Ramp

Bit

Value

Mode

Reference speed

0

const. ascent

1000 rpm (dep.on ud.02)

Acc.

1

const. time

Actual set value

clockwise

0 + 1

2

* const. time

Last set value at constant run

rotation

3

Ogive run

1000 rpm (dep.on ud.02)

0

const. ascent

1000 rpm (dep.on ud.02)

dec.

4

* const. time

Actual set value

clockwise

2 + 3

8

const. time

Last set value at constant run

rotation

12

Ogive run

1000 rpm (dep.on ud.02)

0

const. ascent

1000 rpm (dep.on ud.02)

Acc.

counter-clo-

16

const. time

Actual set value

4 + 5

ckwise rota-

32

* const. time

last set value at constant run

tion

48

Ogive run

1000 rpm (dep.on ud.02)

0

const. ascent

1000 rpm (dep.on ud.02)

dec.

counter-clo-

64

* const. time

Actual set value

6 + 7

ckwise rota-

128

const. time

Last set value at constant run

tion

192

Ogive run

1000 rpm (dep.on ud.02)

* Do not adjust these values - they are only sensible, if acceleration does not take place from standstill or de-

celeration is not made to standstill.

7.4.8.2Ramp with constant time

At the ramp with constant time the acceleration and deceleration times adjusted with oP.28...oP31 always equal

the real ramp times, independent of the set value. In this operating mode S-curves are not possible.

Here an example for the use of ramps with constant time:

Two conveyor belts run with different speeds. Both of them receive the Stop-command at the same time. The

belts reduce the speed in proportion to the adjusted time and come to a standstill simultaneously.

Page7.4 - 20

Setpoint-, Rotation- and Ramp Adjustment

Figure 7.4.8.a Forward acceleration with constant ramp time

n_set

n_actual

t_rampe

t_rampe

t_rampe

t_rampe

t_rampe

t

Figure 7.4.8.b Forward deceleration with constant ramp time

n_set

n_actual

7

t_rampe

t_rampe

t_rampe

t_rampe

t_rampe

t

If the mode constant time is activated for a ramp, then the S-curve function is deactivated for this ramp. The

ascent is limited to minimum to 1000 -1 rpm (dep.on ud.02) 4800 s.

Page7.4 - 21

Setpoint-, Rotation- and Ramp Adjustment

Calculations

Fig. 7.4.8.c

Calculations

n_set

n_2

1000 rpm

delta_n_2

variable

delta_t

delta_n

constant

delta_n

delta_t

constant

delta_t

n_1

delta_n

t_2

constant

delta_t

delta_n_1

variable

delta_t

t

t_1

t_rampe

The speed change per raster scan Δ_t (step size Δ_n) for the mode constant ascent is calculated from the ramp

time t_ramp and the reference speed (1000 rpm dep. on ud.2):

1000 rpm

Δ n =

—————————

t_ramp /Δ t

For different set values the real ramp time is calculated according to following formula:

n_set

t = t_ramp x

—————

1000 rpm

The actual step size for the mode constant time is calculated from the step size delta_n and the actual set

value n_set as follows:

n_set

Δ n(variable) = Δ n x

—————

1000 rpm

For a simplification of the internal calculations 1024 rpm (resp. 2048 rpm or 4096 rpm dependent on ud.2) are

used as reference speed.

n_set

Δ n(variable) = Δ n x

—————

1024 rpm

Page7.4 - 22

Setpoint-, Rotation- and Ramp Adjustment

As a result an error of -2,4 % for the real ramp time occurs. If a certain real ramp time has to be adjusted, the

desired value must be divided by 1.024. Example:

Desired ramp time = 10 s

Adjusted ramp time = 10 s / 1,024 = 9,77 s

7.4.8.3Ogive run

In the mode "constant ascent", a change in setpoint while the inverter is still in the acceleration / deceleration

phase will lead to the fastest possible response. If the new setpoint requires, e.g., a switch from acceleration

to deceleration, the acceleration ramp is interrupted and the deceleration ramp is started immediately. This can

lead to an undefined jolt. If ogive run is selected, the programmed S-curve-times are always used, the accele-

ration / deceleration change continuously, and no undefined jolt occurs.

Figure 7.4.8.3 Ogive run

ru.01: Set value display

ru.02: Ramp output display with

ogive run

7

ru.02: Ramp output display

time

without ogive run

Page7.4 - 23

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