Hitachi WJ Series User Manual page 202

Chapter 9
Confirmation after encoder wiring and related parameter settings
A
 Once complete, check the encoder wiring and related parameter settings by referring to the
table below.
 Run the inverter in forward rotation and reverse rotation while checking the "Current position
monitor [d030]" to confirm that it is counting correctly. (When using the simple position control
function, set "Simple positioning selection [P012]" to "Simple positioning disabled (00)".)
 When the wiring and settings are correct, the [d030] display will add to the "Encoder constant
[P011]" with each forward rotation of the motor, and subtract from the "Encoder constant
[P011]" with each reverse rotation of the motor.
(When the phase order of the R, S, and T phases of the inverter and the U, V, and W phases of
the motor are wired correctly, and when the encoder output is a 90° phase shift pulse input,
phase A will be in the 90° advance phase during forward rotation.)
Event 
Forward and reverse rotation
are reversed.
[d030] does not count.
[d030] does not count when
in forward rotation only, or
when in reverse rotation
only.
Probable cause 
Motor or encoder wiring is
reversed.
Phase A/B pulse inputs from the
encoder are not output
correctly.
Inverter settings are incorrect.
The inverter's input circuit has
failed.
For phases A or B only, this is
caused by the same phenomena
as that described for "[d030]
does not count" above.
Pulse input cannot be counted
correctly due to crosstalk
between encoder A/B phase
signal outputs.
9-5-18
Inverter Functions
Example of countermeasures
Check the motor wiring U, V, and W, and
the encoder phase A and B wiring. If
reversed, rewire correctly.
Check for abnormalities by measuring
the voltage waveforms of the phase A
and B wiring with a multimeter or similar
device.
If the voltage waveform is abnormal,
check the encoder power supply, wiring,
disconnections, etc.
Refer to this section to set the inverter
parameters correctly.
Repair the inverter.
Check the encoder outputs for phase A
and B, and inverter inputs for phase A
and B referring to the above.
Use shielded cables for the A/B phase
wiring cables, and connect the shield to
the L terminal.