Instruction manual 91/121 V6.3
Commissioning
NOTE
: If two or more different analog references are accidentally assigned to the same function, the one that has priority over the
others is the one with the highest number (e.g.: Input AR3 has priority over AR1 input.
PID Speed Loop
Set of parameters to adjust the time constants of the PID adjustment loop on the speed.
NOTE:
random change in these parameters can lead to a worsening of the drive’s performance. It is advisable not to change these
values unless strictly necessary and possibly to contact the ALTER technical office for explanations and clarifications. Please note
that it is possible to return the parameters to the value prior to the change simply by removing the voltage from the services and
then returning it or using the ”Restore“ menu (see page 40), always allowed to NOT have already saved the parameters with
the”Memo Parameters“ menu (see page 40).
Proport. Gain
Minimum Maximum
Units of measure
0
999.00
-
This parameter modifies the Proportional time constant of the velocity loop (see drawing 20). Increasing this value makes the motor
speed more precise than the reference from the outside, but the loop can become unstable (you can hear the motor vibrate). Con-
versely, by decreasing this parameter the motor is more stable but becomes slower in following the speed reference that is given from
the outside.
It is recommended to change this parameter in small steps and test the motor reaction before further changes. When you have found
the right parameter that meets your needs, you can memorise the variations with the “Memo Parameters“ menu (see page 40) and not
before; in this way it will always be possible to return to the previous situation.
Filter PB Pcomp
Minimum Maximum
Units of measure
0 %
100.00 %
-
This parameter modifies the time constant of the Low Pass filter that is outgoing the P component of the velocity loop (see drawing
20). Increasing this value moves to higher frequencies the size point of the filter; conversely, by decreasing the value, the cut fre -
quency is moved to lower frequencies.
In practical use it can be seen that a high value (i.e. around 100 %) makes the filter transparent, i.e. as if it were not there. Instead, re -
ducing the value makes the motor movement more “soft” and with less noise due to adjustment. In certain situations it is possible to
increase the value of the proportional gain and insert this filter to make the loop stable.
Integr. Gain
Minimum Maximum
Units of measure
0
99.00
-
This parameter modifies the Integrative time constant of the velocity loop (see drawing 20). Increasing this value makes the motor’s
reaction to speed variations faster, but the loop can become unstable (you can hear the motor vibrating). The adjustment of this para-
meter leads to benefits especially at low speeds or with a power stationary grip.
It is recommended to change this parameter in small steps and test the motor reaction before further changes. When you have found
the right parameter that meets your needs, you can memorise the variations with the “Memo Parameters“ menu (see page 40) and not
before; in this way it will always be possible to return to the previous situation.
Alter Elettronica s.r.l.
51
Drawing 20: Speed loop
Sp ee d
De m an d
Sp ee d
Feed b ack
-
Sp eed
Error
P
P g ain
I
I gain
D
D gain
Filt er
PB
An t i
Win d u p
Filt er
PB
+
Lim it
Torq ue
Dem and
Dcom p
Pcom p
