
B–63833EN–1/02
1. AXIS CONTROL
77
If the master and slave axes operate independently while simple
synchronous control is applied, the machine may be damaged. To prevent
this, the torque command difference between the axes is monitored. If the
difference is found to be abnormal, an alarm can be issued.
[System configuration]
Position gain
Kp
Kp
Master axis
position
command
-
+
Slave axis
position
command
-
+
Position gain
Velocity control
Master axis
torque command
Master axis position
feedback
Torque command
difference
The absolute value is
compared with the
threshold value.
+
-
Alarm
detection
Slave axis position
feedback
Slave axis
torque command
Velocity control
[How to use]
Determine the threshold parameter using the following procedure.
1 Set up the following parameters:
Parameter No. 2031 = 0 : Disable torque difference alarm detection.
Parameter Nos. 2115 and 2151: Display the absolute value of a torque
difference between axes in synchronization on the diagnosis screen.
Set the same value for the two axes in simplified synchronization.
Setting
Parameter No. 2115 = 0
Parameter No. 2151 = 178
2 Cause the diagnosis screen to appear, using the <SYSTEM> function
key → the [DGNOS] soft key.
The diagnosis screen No. 353 displays the absolute value of a torque
difference between the two axes in synchronization.
3 Read a maximum of the absolute values of torque differences during
a normal operation.
Set the threshold parameter with the maximum absolute value with
some margin allowed.
If it is difficult to read the absolute values of torque differences on the
diagnosis screen, observe the absolute values of torque differences
with an oscilloscope, using the following method:
4 Set parameter Nos. 2115 and 2151 with:
Setting
Parameter No. 2115 = 4
Parameter No. 2151 = 178
D Torque difference alarm
detection (M series)