Projecting with TwinCAT System Manager V2.10
TR-Electronic GmbH 2016, All Rights Reserved
Printed in the Federal Republic of Germany
Page 136 of 153
TR-EMO-BA-GB-0022 v03
09/29/2020
10.9 Profile Velocity Mode (operating mode 3)
At first the velocity encoder factor 0x6094 should be set properly, that converts the
speed units into velocity encoder increments by multiplying. The count of increments
per revolution and second is shown by the object 0x608F:
Velocity Encoder Factor = (Velocity Encoder Resolution)*(Required size of Speed
units in revolutions/sec)
Simple setup of the velocity encoder factor for rpm as speed units:
1 rpm = 1/60 revolution/s
Numerator = Numerator of Vel. Enc. Resolution = 0x80000000
Denominator = Denominator of Vel. Enc. Resolution*60 = 300000
Also see chapter “Units” on page 56.
The remaining set up and turning on of the drive works like the
“Profile Position
Mode
”, see chapter 10.8 on page 133.
Observe following exceptions:
The "Opmode" 0x6060 must be 3.
The "Profile Velocity" 0x6081 is ignored.
A changed "Target Velocity" 0x60FF is evaluated immediately. No control bits must be
toggled. The "Target Position" 0x607A is ignored.
Instead of the "In-Position Window and Time" the "Velocity Window and Time" 0x606D
and 0x606E are used. The "Velocity Window" can be disabled by setting it to 65535.
The digital input bits 2
0
and 2
1
work as lower or negative and upper or positive limit
switches. Refer to chapter 10.6 on page 124.
The status bit 12 zero-speed is set according to the current drive speed, the "Velocity
Threshold" and its timeout.
The "Velocity Threshold" can be disabled by setting it to 0.
The profile reserves the status bit 13 for the slippage error of asynchronous motors.
For servo motors it is useless. For the convenience of users this bit is set again on
following errors, just like in the “Profile Position Mode”, see Status word on page 36.
Just as the operating mode also the target velocity is stored in the non-volatile
memory, unlike any other target value. This is useful for the AUTO-SWITCH-ON
function that turns the drive on without fieldbus, as soon as the power supply reaches
the related voltage threshold.
The drive then can work for example as a stand-alone replacement of a spring.
