ABB ACSM1 Manual page 62

62
Because the drive speed control uses motor speed, a gear function between position
control (load side) and speed control (motor side) is needed. This gear function is
formed from the motor gear function and inverted load gear function. The gear
function is applied to the position control output (speed reference) as follows:
The equation quite often translates to
71.07 GEAR RATIO MUL
71.08 GEAR RATIO DIV
Parameters
of the firmware block
Note: It is emphasised that all position relevant parameters are load side related, eg,
the setting of parameter
300 rpm denotes that, with a load gear ratio of 1:10, the motor can run at up to 3000
rpm.
Examples of gear function usage
The following figures demonstrate how the gear functions of the control program are
used.
1:1
Drive control and features
71.07 GEAR RATIO MUL
71.08 GEAR RATIO DIV
71.07 GEAR RATIO MUL
POS CONTROL
70.04 POS SPEED LIM
Position ref.
Position act.
Load encoder gear
60.03/60.04
Motor speed
=
Load speed
22.03 MOTOR GEAR MUL
=
22.04 MOTOR GEAR DIV
and 71.08 GEAR RATIO DIV
(see page 253).
Gear ratio
71.07/71.08
Position
n1:n2
control
1:1
M
n2:n1
× 60.04 LOAD GEAR DIV
× 60.03 LOAD GEAR MUL
are also inputs
(dynamic limiter speed limitation) of
Speed ref.
Speed act.
Motor encoder gear
22.03/22.04
Mechanical set-up
Drive
hardware
Speed
control
Drive firmware