Danfoss MCO 305 Design Manual page 215

MCO 305 Design Guide
32-83 Velocity Resolution
VELRES
Range
1 – 10000
Function
The Velocity Resolution VELRES defines a relative
size for the velocity values of the motion com-
mands and parameters. The information concer-
ning speed and acceleration can then be made in
whole numbers in relation to this scaling. The value
100 means that the information in the commands
are related to 100, thus in percent.
32-84 Default Velocity
DFLTVEL
Range
1 – p. 32-83 VELRES
Function
Default Velocity indicates the default velocity which
is always used when no velocity is defined in the
process set. This value refers to the Velocity
Resolution VELRES.
32-85 Default Acceleration
DFLTACC
Range
1 – p. 32-83 VELRES
Function
Default Acceleration indicates the acceleration used
when no explicit statements have been made. This
statement is made in relation to par. 32-81 Shor-
test Ramp and refers to the par. 32-83 Velocity
Resolution.
32-86 Acc. up for limited jerk
JERKMIN
Range
0 ... MLONG [ms]
Function
Acceleration ramp-up constant for limited jerk
movements. This specifies the time in ms required
to ramp the acceleration up from 0 to maximum
acceleration.
default setting
__ Parameter Reference __
100
50
50
100
[ ] value for use in communication via serial communication port
®
MG.33.L5.02 – VLT is a registered Danfoss trademark
There are four different JERKMIN options, see
"Limited Jerk" in chapter "Function and Examples"
and the parameter 32-87, 32-88, and 32-89.
The maximum Jerk used with par. 32-82 Ramp
Type = 2 is calculated by JERKMIN using following
formulas:
Maximum
Max. Accelerati on =
Par. 32
Maximum
Maximum Jerk =
Par. Jerk
Note, that par. 32-81 Shortest Ramp and Jerk
Duration are time values in milliseconds.
NB!:
A changed setting of JERKMIN is executed
after the next movement command
(POSA, POSR, CVEL, or MOTOR STOP) and
used for the calculation of the acceleration. Thus it
is possible in NOWAIT ON mode with a repeated
POSA command to adapt during a movement
online (i.e. without stop) the movement to new
definition.
NB!:
Starting with MCO 5.00 the Parameter
Jerk Duration JERKMIN is available in the
axis parameter field "Basic Settings".
Sample
Calculation sample:
VELMAX = 3000 [RPM]
ENCODER = 500 counts/rev [PPR]
RAMPMIN = 500 ms
JERKMIN = 200 ms
This results in:
VELMAX = 3000 * 500 *
= 100 qc/ms
MaxAcc = 200,000 qc/s
MaxJerk = 1,000,000 qc/s
32-87 Acc. down for limited jerk
JERKMIN2
Range
0 ... MLONG [ms]
Velocity
- 81 Shortest Ramp
Accelerati on
Duration JERKMIN
4
= 100,000 qc/s
60
2 2
= 0.2 qc/ms
3 3
= 0.001 qc/ms
215
0