YASKAWA SGD7S Product Manual page 150

5.8 Selecting the Phase Sequence for a Linear Servomotor
Operating Procedure
Use the following procedure to select the phase sequence for a Linear Servomotor.
1.
Set Pn000 to n.0 (Set a phase-A lead as a phase sequence of U, V, and W).
This setting is to make following confirmation work easier to understand.
2.
Select Monitor in the Menu Dialog Box.
The Operation Pane will be displayed so that you can check the feedback pulse counter.
To check the feedback pulse counter with the Digital Operator, use Un00D (Feedback Pulse Counter).
3.
Manually move the Moving Coil from one end to the other of the stroke and confirm that
only the correct number of feedback pulses is returned.
If the correct number and only the correct number of pulses is returned, the signal is being received
correctly from the linear encoder.
Information
4.
Manually move the Moving Coil in the direction of the cable and check the value of the
feedback pulse counter in the Operation Pane to confirm that it is counting up.
If the pulses are counted up, the forward direction of the Linear Servomotor is the same as the count-
up direction of the linear encoder.
5.
If the feedback pulse counter counts down, set a phase-B lead as a phase sequence of
U, V, and W (Pn080 = n.1) and turn the power supply OFF and ON again.
6.
If necessary, return Pn000 = n.X (Direction Selection) to its original setting.
This concludes the procedure to set the phase sequence of the Linear Servomotor.
5-22
In this example, assume that a linear encoder with a scale pitch of 20 μm and a resolu-
Example
tion of 256 is used. If you manually move the Moving Coil 1 cm in the count-up direction
of the linear encoder, the number of feedback pulses would be as follows:
1 cm/(20 μm/256) = 128,000 pulses
If there are 128,000 pulses on the feedback pulse counter after
you manually move the Moving Coil in the direction of the cable,
you have completed the confirmation.
Note: The actual monitor display will be offset by the error in the travel distance. There is no
problem as long as the above value is close to the calculated value.
If the correct value is not displayed for the feedback pulse counter, the following condi-
tions may exist. Check the situation and correct any problems.
• The linear encoder pitch is not correct.
If the scale pitch that is set in Pn282 does not agree with the actual scale pitch, the
expected number of feedback pulses will not be returned. Check the specifications of
the linear encoder.
• The linear encoder is not adjusted properly.
If the linear encoder is not adjusted properly, the output signal level from the linear
encoder will drop and the correct number of pulses will not be counted. Check the
adjustment of the linear encoder. Contact the manufacturer of the linear encoder for
details.
• There is a mistake in the wiring between the linear encoder and the Serial Converter
Unit.
If the wiring is not correct, the correct number of pulses will not be counted. Correct
the wiring.
If the feedback pulse counter counts up when you manually move the Moving
Coil in the direction of the cable, you have completed the confirmation.
Cable for Linear
Servomotor Moving Coil
Cable for Linear Servomotor
Moving Coil