
3
Cycle Error (
C):
An indication
of cycle uniformity. The differ-
ence between an observed shaft
angle which gives rise to one
electrical cycle, and the nominal
angular increment of l/N of a
revolution .
Pulse Width (P):
The number of
electrical degrees that an output
is high during 1 cycle. This value
is nominally 180
°
e or 1/2 cycle.
Pulse Width Error (
P):
The
deviation, in electrical degrees, of
the pulse width from its ideal
value of 180
°
e.
Definitions
Count (N):
The number of bar
and window pairs or counts per
revolution (CPR) of the
codewheel.
One Cycle (C):
360 electrical
degrees (
°
e), 1 bar and window
pair.
One Shaft Rotation:
360
mechanical degrees, N cycles.
Position Error (
Θ)
:
The
normalized angular difference
between the actual shaft position
and the position indicated by the
encoder cycle count.
Output Waveforms
State Width (S):
The number of
electrical degrees between a
transition in the output of channel
A and the neighboring transition
in the output of channel B. There
are 4 states per cycle, each
nominally 90
°
e.
State Width Error (
S):
The
deviation, in electrical degrees, of
each state width from its ideal
value of 90
°
e.
Phase (
φ
):
The number of
electrical degrees between the
center of the high state of channel
A and the center of the high state
of channel B. This value is
nominally 90
°
e for quadrature
output.
Phase Error (
φ
):
The deviation
of the phase from its ideal value
of 90
°
e.
Direction of Rotation:
When the
codewheel rotates in the direction
of the arrow on top of the
module, channel A will load
channel B. If the codewheel
rotates in the opposite direction,
channel B will lead channel A.
Optical Radius (R
OP
):
The
distance from the codewheel’s
center of rotation to the optical
center (O.C.) of the encoder
module.
Index Pulse Width (P
o
):
The
number of electrical degrees that
an index is high during one full
shaft rotation. This value is
nominally 90
°
e or 1/4 cycle.
Absolute Maximum Ratings
Storage Temperature, T
S
................................................. -40
°
C to 140
°
C
Operating Temperature, T
A
............................................. -40
°
C to 140
°
C
Supply Voltage, V
CC
............................................................ -0.5 V to 7 V
Output Voltage, V
..............................................................-0.5 V to V
Output Current per Channel, I
OUT
.................................-1.0 mA to 5 mA
Shaft Axial Play.................................................
±
0.25 mm (
±
0.010 in.)
Shaft Eccentricity Plus Radial Play..................... 0.1 mm (0 004 in.) TIR
Velocity........................................................................... 30,000 RPM
[1]
Acceleration............................................................. 250,000 rad/sec
2[1]
Note:
1. Absolute maximums for HEDS-5140 codewheel only.