8
Installation
Note:
Normally, ground the cable shield only at the drive end. However,
if the encoder is isolated from the motor, and from ground, then connect
the cable shields to both the OTAC module and the encoder housing.
Note:
Do not route the encoder cables parallel to power (e.g. motor)
cables.
3. Verify correct encoder phasing. See options below.
Phasing
When the encoder is connected correctly, running the drive in the
Forward
(positive speed reference) direction should produce a positive
encoder speed feedback.
Option A: Oscilloscope Test.
On incremental encoders, the two
output channels, usually marked A and B or 1 and 2, are 90° (electrical)
apart from each other. When rotated clockwise, most encoders – but
not all – have channel A/1 leading channel B/2 as illustrated below.
Determine the leading channel by referring to the encoder
documentation or by measuring with an oscilloscope.
The encoder output channel that leads when the drive runs
Forward
should be connected to OTAC terminal A. The output channel that trails
should be connected to OTAC terminal B.
Option B: Functional Test.
For this test:
• Temporarily, switch the drive to scalar mode (parameter 9904 = 3), if
not already there.
A or 1
A or 1
B or 2
B or 2
Z or 0
Z or 0
Diagrams show normal phasing:
Pulse A/1 leads (i.e. rises earlier than)
pulse B/2.
90°
Connect the zero reference output
channel (usually marked 0, N or Z)
only if parameter 5010
Z
PLS
ENABLE
=
1 (
ENABLE
).
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