Magnetek TM7310rev01 Benutzerhandbuch

 

The drive speed command is passed through 
an internal S-curve in order to produce the 
speed reference.  In general, the S curve 
function takes an arbitrary speed command 
and generates a speed reference subject to 
the conditions that the maximum accel, decel 
and jerk rates not be exceeded. The speed 
command is typically the target speed that the 
reference is headed to. 

If the user gives the drive a speed dictation, 
either analog or serial, the S-Curve will act as 
a slew rate limiter on the externally generated 
speed dictation.  For this purpose, set the jerk 
rates associated with the S-Curve (see Table 3 
for determining which s-curve is used) to zero 
and the Accel Rate and Decel Rate to values 
faster than the maximum expected rated 
provided in the dictation signal. 

Below shows the six parameters associated 
with an S-Curve data set: 

•  Accel - Maximum allowed acceleration rate 

(ft/s

2

 or m/s

2

) 

•  Decel - Maximum allowed deceleration rate 

(ft/s

2

 or m/s

2

) 

•  Accel Jerk In - Maximum allowed change in 

acceleration towards Accel (ft/s

3

 or m/s

3

) 

•  Accel Jerk Out - Maximum allowed change 

in acceleration from Accel (ft/s

3

 or m/s

3

) 

•  Decel Jerk In - Maximum allowed change in 

deceleration towards Decel (ft/s

3

 or m/s

3

) 

•  Decel Jerk Out - Maximum allowed change 

in deceleration from Decel (ft/s

3

 or m/s

3

) 

 
The S-curves are specified by four parameters: 
acceleration rate (ft/s

2

 or m/s

2 

), deceleration 

rate (ft/s

2

 or m/s

2

), leveling jerk rate (ft/s

3   

or  

m/s

3 

), and jerk rate (ft/s

3   

or  m/s

3 

).  

 
Since an adjustable jerk rate is helpful for 
smooth landings, the jerk rates are split for 
ease in elevator fine-tuning.  The jerk rate 
parameters specify: acceleration from the floor 
(ACCEL JERK IN), jerk out of acceleration 
(ACCEL JERK OUT), jerk into deceleration 
(DECEL JERK IN), and the leveling into the 
floor (DECEL JERK OUT). 

   
 

 

S-Curve 

There are four S-curve patterns available in 
the drive and each S-curve is customized by 
six parameters: 
Parameters for S-curve-0 (SC0): 

•  ACCEL RATE 0, DECEL RATE 0, ACCEL 

JERK IN 0, ACCEL JERK OUT 0, DECEL 
JERK IN 0, and DECEL JERK OUT 0 

Parameters for S-curve-1 (SC1): 

•  ACCEL RATE 1, DECEL RATE 1, ACCEL 

JERK IN 1, ACCEL JERK OUT 1, DECEL 
JERK IN 1, and DECEL JERK OUT 1 

Parameters for S-curve-2 (SC2): 

•  ACCEL RATE 2, DECEL RATE 2, ACCEL 

JERK IN 2, ACCEL JERK OUT 2, DECEL 
JERK IN 2, DECEL JERK OUT 2 

Parameters for S-curve-3 (SC3): 

•  ACCEL RATE 3, DECEL RATE 3, ACCEL 

JERK IN 3, ACCEL JERK OUT 3, DECEL 
JERK IN 3, DECEL JERK OUT 3 

 

S-Curve Pattern Selection 
The default S-curve pattern is S-curve-0 
(SC0).  To make the other patterns available, 
the user must assign S-CURVE SEL 0 and/or 
S-CURVE SEL 1 as logic input(s).  The logic 
input(s) can then be used to select one of the 
S-curve patterns, as follows: 
 

Logic Inputs 

Assigned 

S-curves 

Available 

None SC0 

only 

SEL 0 only 

SC0 or SC1 

SEL 1 only 

SC0 or SC2 

SEL 0 & SEL 1 

SC0, SC1, 

SC2 or SC3 

 

 

logic input 
S-CURVE 

SEL 1 SEL 

0 

S-curve 

selected 

0 0 

SCO 

0 1 SC1 
1 0 SC2 
1 1 SC3 

 

 

39