Control Techniques M'Ax, Advanced User'S Manual

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M’Ax Advanced User Guide
16
Issue Number: 4 www.controltechniques.com
This parameter defines the maximum rate of change of acceleration/deceleration. The default values have been chosen such that for the
default ramps and maximum speed, the curved parts of the S will be 25% of the original ramp if S-ramp is enabled.
Since the ramp rate is defined in second
2
/1000rpm and the S-ramp parameter is defined in second
2
/1000rpm, the time T for the 'curved' part
of the S can be determined from:
T = S-ramp rate of change / Ramp rate
Enabling S-ramp increases the total ramp time by the period T since an additional T/2 is added to each end of the ramp in producing the S.
The acceleration rate is selected as follows.
0 Ramp rate selection by terminal input
1 ~ 4 Ramp rate defined by parameter number, i.e. 1 = 2.11, 2 = 2.12
5 Ramp rate selection by parameter 1.50
When parameter 2.10 is set to 0 the acceleration ramp rate selected depends on the state of bit parameters 2.32 to 2.33. These bits are for
control by digital inputs such that ramp rates can be selected by external control. The ramp rate selected depends on the binary code
generated by these bits as follows:
When parameter 2.10 is set to 5 the appropriate acceleration rate is automatically selected depending on the value of parameter 1.50, and so
an acceleration rate can be programmed to operate with each preset reference. Since the new ramp rate is selected with the new reference,
the acceleration applies towards the selected preset if the motor needs to accelerate to reach the preset.
Refer to parameter 2.10.
2.07 S-ramp acceleration limit
ô
0.000 ~ 32.000
ð
0.031
s
2
/1000rpm
RW Uni
2.10 Acceleration rate selector
ô
0 ~ 5
ð
0 RW Uni
2.33 2.32
Ramp
defined by
0 0 2.11
0 1 2.12
1 0 2.13
1 1 2.14
2.11 Acceleration rate 1
ô
0.000 ~ 32.000
ð
0.200 s/1000rpm RW Uni 0.25
2.12 Acceleration rate 2
2.13 Acceleration rate 3
2.14 Acceleration rate 4
ô
0.000 ~ 32.000
ð
0.200 s/1000rpm RW Uni
Programmed
ramp rate
S-ramp
acceleration
ramp
Demand Speed
Acceleration
Actual Speed