FATEK SD3 Series - Problem 5. Positional Aberration

22
8. Troubleshooting
SD3 Series Instruction Manual
４. Troubleshooting
Problem 5. Positional aberration
Cause Remedy
The command signal is interfered
with noise.
In Position Control/Pulse Train Command
Set Pulse train command Input lter (No.33.0) to an appropriate value.
Check the following three items.
1. Status No.33 (Pulse Train Command Input (position) agrees with the host
controller output.
2. Status No.65 "Position command" and Status No.67 "Position feedback"
agree.
3. (Status No.67) x (Encoder pulse ratio (No.276.0/No.278.0)
= (Position feedback from the host control device)
If any of the above conditions fails, take countermeasures for noise.
Connect FG correctly.
Adjust Pulse train command: Input lter (No.33.0)
Select a shielded twist-pair wire for the I/O cable.
For the encoder cable, select a shielded twist-pair wire of no longer than 20 m.
The position deviation is not
converging.
Verify that Status No.65 (Position command value) and Status No.67 (Position
feedback) agree.
If not, adjust the tuning parameters.
The host controller is not obtaining
encoder Z-phase correctly.
Check the command from the host controller.
Use "Servo Studio" to measure the waveforms of Status No.33 "Pulse Train
Command
Input (position)" or Status No.49 "Analog Velocity Command Input" to verify
that a normal command is input.
Verify that the host controller is obtaining Z-phase correctly. If the Z-phase
pulse width is too small, increase the pulse width by using the Encoder pulse
ratio (No.276.0/No.278.0) As a rule of thumb, the pulse width of 1 ms or
above is required for PLC.
Output pulse frequency of
the host controller is above
the upper limit.
Verify that the output pulse frequency of the host controller such as PLC is
not above the upper limit.
A resistor is installed in the pulse
output circuit of the host controller
(PLC).
Verify that there is no built-in resistor in pulse output terminal.
The output resistor of the host controller and the input resistor of servo
amplier being connected in series prevents correct command signal from
being input to the amplier.
The motor does rotate, but position aberration occurs.