User`s manual

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9
Stepping driver
JW-12PS
Encoder (PG)
[2] Mode 1
In this mode, errors are monitored according to the feedback data. An error is judged to stop
operation when the coordinate value according to the output pulse and the coordinate value
captured from the encoder have exceeded a fixed value (closed loop control allowable range).
(Errors are monitored at all times during operation.)
When output of all instruction pulses is completed and then positioning does not fall within the
completion pulse allowable range within the positioning monitoring time, the completion range error
(017) is output and operation is stopped. Note, however, that when the completion signal was set to
"enabled," the completion pulse allowable range is ignored, and judgment as to whether or not
positioning completed by the completion signal is performed. (See the list relating to various setting
values and operations.)
In this mode, compensation is not performed even if a shift occurs in the instruction value and
feedback value.
This mode is used mainly for judgment as to whether the stepping motor is out of sync. Set the
closed loop allowable range in instruction pulse control units.
(Note) When judging whether the stepping motor is output of sync, set the closed loop control
allowable range to 1/50 or more of the maximum instruction speed. For example, when the
maximum instruction speed is 50 kpps, the closed loop control allowable range must be set
to 1000 pulses or more.
In systems that use a servo, normally, deviation is judged on the driver side. So, set the
closed loop control allowable range to "0". When this range is set to "0", only the allowable
range at completion is monitored in this mode.
Example
When the closed loop control allowable range is set to 500 and the completion pulse allowable
range is set to 50, 5000 pulses is being output while JW-12PS is operating, the number of pulses
from the encoder has fallen to 4500 or less.
An error (error 017) is also judged and an error is output when 10000 pulses are output as the
instruction value at the final coordinate, operation ends, and the feedback pulse is 9950 or less.
• Set the ratio between the number of instruction pulses and number of feedback pulses from the
encoder in parameters in advance.