Wiring Check Function - Omron CS1W-MC221 - 02-2008 Operation Manual

Wiring

2-3-10 Wiring Check Function

Test pulses
132
In order to prevent this, repair the wiring or adjust the 0 V of either the MC Unit
or the servo driver so that the 0 V levels match, and, to be on the safe side,
implement fail-safe measures in the system.
The MC Unit is provided with a wiring check function. This function is
designed to check for reverse wiring and disconnected wiring when the power
supply switch is turned on in order to prevent motor runaway. Whether or not
to a execute wiring check can be determined by setting a system parameter.
For details on troubleshooting when performing the wiring check, refer to Sec-
tion 2-5 Wiring Check Troubleshooting.
This function is designed to output a specified number of pulses in the speci-
fied direction and to check whether correct feedback pulses are read.
Amp
Error
counter
Direction
discrimination
circuit
Set a specified number of test pulses in the error counter. After a set period of
time (the time required for the system parameter to perform wiring check),
check the content of the error counter to determine whether the number of
pulses that were initially set and also the direction are correctly returned.
When the test pulses are set in the CW direction, the feedback pulses corre-
sponding to the set number of pulses will be returned in the CW direction. If
the direction is reversed, it is treated as a reverse wiring error and the servo-
lock is cleared, dropping the voltage output to 0 V.
To correct this faulty wiring, either turn OFF the power and repair 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."
In addition to the descriptions on the previous page, if the feedback pulses
returned is less than the number of test pulses, a disconnected wiring error
will be generated. Just as with a faulty wiring error, the servolock will be
cleared and the voltage output will drop to 0 V.
To correct a disconnected wiring, turn OFF the power and repair the wiring.
Disconnected wiring errors can also be generated from errors other than wir-
ing errors, such as failure of internal MC Unit components, servo driver errors,
and so on.
Faulty wiring checks and disconnected wiring checks can be carried out
simultaneously. Both checks can be skipped by setting the machine parame-
ter "wiring check" from the MC Support Software to NO. It is initially set to
YES.
The settings for specifying whether a wiring check will be performed, deter-
mining the wiring check time, and specifying the number of pulses, are all
Control
voltage
Servo
driver
Phase A/B feedback
Section 2-3
Servomotor
Encoder