HEDS-974X Datasheet, PDF (2/6 Pages) Agilent(Hewlett-Packard) – 180, 300, 360 LPI Small Optical Encoder Modules

Definitions
Count (N) = the number of bar
and window pairs or Counts Per
Revolution (CPR) of the
codewheel, or the number of
Lines Per Inch (LPI) of the
codestrip.
1 Shaft Rotation = 360 mechanical
degrees
= N cycles
1 Cycle (c) = 360 electrical
degrees (°e)
= 1 bar and window pair
Pulse Width (P): The number of
electrical degrees that an output
is high during one 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.
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 four 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 counter-
clockwise, as viewed looking
down on the module (so the
marking is visible), channel A will
lead 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 (OC) of the encoder
module.
Angular Misalignment Error
(E_A): Angular misalignment of
the sensor in relation to the
tangential direction. This applies
for both rotary and linear motion.
Mounting Position (R_M):
Distance from motor shaft center
of rotation to center of alignment
tab receiving hole.
Absolute Maximum Ratings
Parameter
Storage Temperature
Operating Temperature
Supply Voltage
Output Voltage
Output Current per Channel
Soldering Temperature
Symbol
Min.
T_S
–40
T_A
–40
V_CC
–0.5
V_O
–0.5
I_O
–1.0
Max.
85
85
7
V_CC
5
260
Units
°C
°C
V
V
mA
°C
Notes
t ≤ 5 sec.
2