
Individual Functions
6-
133
Fig 6.70 Torque Control Block Diagram
Speed Limiter and Priority Circuit (Speed Limit Function)
If the external torque reference and load are not balanced during torque control, the motor will accelerate in
either the forward or reverse direction. The speed limit function is used to limit the speed to a specified value
and it consists of the speed limiter circuit and priority circuit.
When the motor speed exceeds the speed limit value during torque control, the speed limiter circuit generates
the suppression torque proportional to the speed above the limit value and adds to the torque reference. The
priority circuit switches the internal torque reference to ASR output so that the motor speed does not exceed
the speed limit value.
Application Precautions
There are two ways to set a speed limit: using an input from an analog input terminal and setting a speed limit
in d5-04. The inputs methods for a speed limit are listed in the following table.
Speed Limit Input Method
Location of
Reference
Constant
Settings
Remarks
Constant setting
Set in d5-04
d5-03 = 2
–
Voltage input (-10 to 10 V)
Between A1 and AC
b1-01 = 1
H3-01 = 1
Set H3-01 to 0 if the speed limit between
terminals A1 and AC is always to be posi-
tive.
Between A2 and AC
b1-01 = 1
H3-08 = 1
H3-09 = 0
The sum of the values of terminals A1 and
AC and terminals A2 and AC are the
speed limit. Set H3-09 to 1 to set the speed
limit to the multiplied values of terminals
A1 and AC and terminals A2 and AC. Set
H3-08 to 0 if the speed limit input on A2
is always to be positive.
Turn OFF (V side) DIP switch pin S1-2 on
the terminal board.
Current input (4 to 20 mA)
Between A2 and AC
b1-01 = 1
H3-08 = 2
H3-09 = 0
The sum of the values of terminals A1 and
AC and terminals A2 and AC are the
speed limit. Set H3-09 to 1 to set the speed
limit to the multiplied values of terminals
A1 and AC and terminals A2 and AC.
Turn ON (I side) DIP switch pin S1-2 on
the terminal board.
Torque reference
from analog input
Torque primary delay
filter
d5-02
Torque compensation
from analog input
Speed limit from analog
input from terminal A1
Speed limit
d5-04
1
2
d5-03
Speed limiter
Speed feedback
Speed limit bias
d5-05
+
Torque limit
Internal torque
reference
Refer to torque limit setting
via constants and analog input
Speed controller
(ASR)
Priority
circuit
+
+
+
−
TOE-S616-60.1.book 133 ページ 2017年8月4日 金曜日 午後3時41分