Encoders
7–14
Description
Bulletin 844A blind-shaft and 844B
through-shaft incremental encoders are
used to electronically monitor the
position or speed of a rotating shaft.
Shaft position is converted to digital
pulses in an A quad B format.
S
Blind or through-shaft designs
S
Integral flex mount
S
10 to 2500 PPR
S2I
diameter housing
Bulletin 844A and 844B encoders offer
a built-in flexible coupling which
reduces installation cost and mounting
space requirements. Additionally
, the
Bulletin 844B Encoder is a through-
shaft design allowing additional
accessories to be mounted to the same
shaft. Both families come standard with
channels A, B and Z and dif
ferential line
driver (DLD) outputs. Single-ended
outputs are also supported at no
additional charge. All support shaft
sizes up to 1/2
I
in diameter
. Bulletin
844A and 844B Encoders of
fer 42
resolution options.
Specifications
Bulletin
844A & 844B Blind & Through-Shaft Optical Incremental Encoders
Housing
Temperature
Humidity
Protection
Shock
Vibration
Approximate Weight
Code Format
Quadrature
Symmetry
Power Requirements
Max Output Frequency
Resolution
Integral Cable
Output Drivers
Aluminum
0_C to 70_C (+32_F to +158_F)—Operating
–20_C to 85_C (–4_F to +185_F)—Storage
95% noncondensing
IP40 (IEC529)
20g/11ms
5g/10–150Hz
0.12kg (4oz)
Angular Acceleration
Moment of Inertia
Maximum Operating Speed
Permissible Shaft Movement
Shaft Loading
Shaft Size
50,000 radians/sec2
19.4gcm2 (2.75 x 10–4 oz-in-sec2)
3000rpm at max shaft loading
Radial 0.13mm (0.005in)
Axial ±0.76mm 〈±0.030in)
Axial 0.45kg (1lb)
Radial 1.36kg (3lb)
3/8I or 1/2I
2 channels with zero index
90_ ±22_ channel A leads B CW
40% to 60%
120mA (no load)
100kHz
Up to 2500 pulses per revolution
457mm (18in)
RS422 Line driver—3487
Open collector—7406
8–24V Line driver—7272
Electrical
Mechanical
Environmental
Encoders
7–15
Selection Guide
844 A —Z3 05C 2500
a b c d
a
Coupling Options
Code Description
AFront
(Blind-Shaft)
B
Rear (Through-Shaft)
b
Shaft Options
Code Description
Z3 3/8I
Z4 1/2I
Accessories
Description Page
Number
Differential Encoder
Buffer Board
7–58
c
Power Supply & OutputÊ
Code Description
05D 5V DC In,
5V DC DLD RS–422 Out
05C 5V DC In,
NPN Open Collector Out
12C 12V DC In,
NPN Open Collector Out
24D 8–24V DC In,
8–24V DC DLD Out
Ê
DLD = Dif
ferential Line Driver
d
Resolution (PPR)
Code Description
0010 10
0020 20
0030 30
0050 50
0060 60
0100 100
0128 128
0150 150
0180 180
0200 200
0240 240
0250 250
0256 256
0300 300
0336 336
0360 360
0400 400
0500 500
0512 512
0600 600
0720 720
0800 800
0900 900
0960 960
1000 1000
1024 1024
1140 1140
1152 1152
1200 1200
1230 1230
1250 1250
1260 1260
1270 1270
1386 1386
1500 1500
1512 1512
1800 1800
1888 1888
2000 2000
2048 2048
2400 2400
2500 2500
Bulletin
844A & 844B Blind & Through-Shaft Optical Incremental Encoders
Encoders
7–16
Electrical Connections
Function
Line
Driver
Wire Color
Open Collector
Wire Color
V DC Red Red
Common Black Black
A Output White White
B Output Green Green
Z Output White/Black White/Black
A Output Blue NC
B Output Orange NC
Z Output Red/Black NC
Shield Drain Wire Drain Wire
Output Waveforms
1. Channel
A leads Channel B for
clockwise rotation when viewed
from face of the encoder
.
2.
Complementary signals (A, B, and
Z) are supplied only on units with
line drivers.
3.
Marker Pulse is nongated and is
approximately centered on the
positive-going edge of Channel B
for clockwise rotation and is 180
_
±
90_
wide.
A
B
Z
Channel
Dimensions—mm (inches)
9.55/9.60
(0.376/0.378)
12.73/12.78 (0.501/0.503) Dia.
9.55/9.60 (0.376/0.378)
12.73/12.78 (0.501/0.503) Dia.
#3–48
Head Cap
Screw
∅24.9
(0.98)
5.08
(0.20)
#3–48
Head Cap
Screw
∅60.3
(2.37)
∅68.6
(2.70)
10_
4.57
(0.18)
457
(18.0)
Shielded
Cable
29.7
(1.17)
Max
∅60.3
(2.37)
30_
40_
Typ
3.3
(0.13)
Typ
∅68.6
(2.70)
10_
30_
∅50.8
(2.00)
40.6
(1.60)
Max
76.2
(3.0)
30_
3.3
(0.13)
Typ
40_
Typ
30_
76.2
(3.0) 457
(18.0)
29.2
(1.15)
42.7
(1.68)
∅50.8
(2.00)
Bulletin 844A
Bulletin 844B
844A Mating Shaft Tolerance—
mm (inches)
Bore Diameter Length
3/8I9.50/9.55
(0.374/0.376)
10.7/31
(0.42/1.22)
1/2I12.67/12.73
(0.499/0.501)
10.7/31
(0.42/1.22)
844B Mating Shaft Tolerance—
mm (inches)
Bore Diameter
Length
(minimum)
3/8I9.50/9.55
(0.374/0.376)
41 (1 6)
1/2I12.67/12.73
(0.499/0.501)
41 (1.6)
Bulletin
844A & 844B Blind & Through-Shaft Optical Incremental Encoders
