Wiring Error Cause And Countermeasures - Omron CS1W-MC221 - 02-2008 Operation Manual

Wiring Check Troubleshooting
2-5-3

Wiring Error Cause and Countermeasures

!Caution When a wiring error occurs, be sure to turn OFF the power supply before
Cause of error
Wiring is faulty or disconnected.
The wiring is reversed for feedback
pulses or speed reference.
There is a speed reference offset.
(The zero balance is distorted.)
There is weight or external force on an
axis.
The machinery is too heavy.
Some component in the MC Unit has
failed.
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As explained above, wiring errors can occur for reasons other than actual wir-
ing problems. The following table list possible causes of such errors, and sug-
gests countermeasures that can be taken.
checking the wiring or setting the machine parameters.
Contents
Feedback pulses were not returned
within the wiring check time period, so
a wiring error was generated. The
wiring check function is operating
normally.
Feedback pulses were returned in the
opposite direction from the specified
direction of movement, so a wiring
error was generated. The wiring check
function is operating normally.
The MC Unit's 0 V command reference
does not match that of the servo drive.
Even after the wiring check time has
elapses, a wiring error (reverse wiring
error) may be generated if weight or
external force causes reverse
movement.
Feedback pulses are not returned
within the specified wiring check time
because the machinery is too heavy.
• If there is a problem with the power
supply circuitry or the analog circuitry
in the MC Unit, the speed reference
voltage will not be output correctly.
• If there is a problem with the
feedback circuitry, feedback pulses
will not be returned.
Section 2-5
Countermeasures
Check for faulty wiring or
disconnections.
Correct the reversed wiring or change
the machine parameter "encoder
polarity" from the preset setting to the
opposite setting, i.e., change from
"forward rotation for encoder increase"
to "reverse rotation for encoder
increase" or from "reverse rotation for
encoder increase" to "forward rotation
for encoder increase."
Connect the MC Unit to the servo
driver, turn ON the power supply, and
adjust the 0 V at the servo driver with
servo-lock disabled.
For U-, W-, and G-series Servo Drivers,
execute an automatic offset adjust-
ment. An automatic offset adjustment
is an adjustment for reading the
present input voltage as 0 V. Only U-,
W-, and G-series Servo Drivers have
this function.
• It is a bit difficult for a wiring check,
but it is possible to set a speed
reference offset that just corresponds
to the weight or external force.
• If reverse movement due to weight or
external force cannot be avoided, as
a temporary measure set the wiring
check so that it will not be executed.
• Set the number of wiring check
pulses and the wiring check time to
double their original values, and
execute the check again.
• Increase the gain so that the
feedback pulses are returned within
the wiring check time.
If the error persists even after the
above countermeasures have been
tried, there may be a component failure
in the MC Unit. Replace the MC Unit.