Encoders
7–20
English Servo Mount
845D–SJHZ14BDCK2
Description
The
Bulletin 845D is a heavy duty
,
NEMA T
ype 4 single-turn absolute
position encoder that digitizes shaft
angle position into one of a number of
absolute code formats. The absolute
encoder has a unique digital output for
each shaft position. The use of absolute
encoders assures that true position is
always available, regardless of power
interruptions to the system.
The Bulletin 845D employs a single
laser diode and a fiber optic assembly
to produce a concentrated beam of light
that is passed through a code disk and
sensed as high level optical signals by
Rockwell Automation/Allen-Bradley’
s
custom hybrid array
. The Bulletin 845D
of
fers increased reliability by eliminating
the need for a complex multi-lens
assembly used in other absolute
encoders.
The Bulletin 845D provides improved
accuracy, increased operating speed
and high noise immunity over
competitive units. The 845D is housed
in a size 25 NEMA T
ype 4 enclosure to
meet the demands of today’
s industrial
environment.
Features
S
Absolute Gray Code, Natural Binary
or BCD output
S
Optional latch command input for
discrete I/O
S
Optional 5V
, or 8–24V DC power
requirements
S
CE marked for all applicable
directives
Specifications
Accessories
Description Page
Number
Flexible Couplings 7–50
Measuring Wheels 7–51
Servo Clamps 7–51
Pre-Wired Cables
7–52
Mating Connectors 7–55
Mounting Plates 7–55
Bulletin
845D Optical Absolute Encoders
NEMA Type 4, Single-Turn, Size 25
Absolute binary coded decimal (BCD)
Gray code (GRAY)
Natural binary (NAT BIN)
(GRAY and NAT BIN): 256 CPR (8 bit); 512 CPR (9 bit)
1024 CPR (10 bit)
(BCD): 360 CPR (10 bit); 1000CPR (12 bit)
±1/2 least significant bit
25K words/sec
Determined by catalog number: 5V DC ±5% @ 400mA maximum
8–24V DC @ 400mA maximum
NPN current sink = 16mA
Parallel BCD, GRAY, or NAT BIN: Logic “0” = 0.0 to 0.6V DC
Logic “1” = 3.5 to 5.0V DC (TTL)
Logic “1” = 24V DC maximum
(Open collector)
Optional with BCD and NAT BIN only: Logic “0” = outputs active
Logic “1” = outputs latched
Field selectable for increasing counts (CW or CCW)
2.5 Ncm typical [3.5in-oz]
Axial 89N [20lbs]; Radial 178N [40lbs]
6mm, 10mm, 1/4in, 3/8in diameter
15gcm2 (2.1 x 10–4oz-in–sec2)
6000 RPM
NEMA Type 4, IP66 (IEC 529); NEMA Type 4X on selected models
0°C to +60°C (+32°F to +140°F )—operating
–25°C to +90°C (–13°F to +194°F)—storage
98%, noncondensing
50g (1
1ms duration)
20g (5 to 2000Hz)
0.91kg (2lbs)
Code Format
Resolution
Accuracy
Frequency Response
Power Requirements
Output Drive Capability
Output Logic
Latch Command
Direction Control
Starting and
Running Torque
Shaft Loading
Shaft Size
Moment of Inertia
Slew Speed
Housing
Temperature
Humidity
Shock
Vibration
Approximate Ship Weight
Electrical
Mechanical
Environmental
Encoders
7–21
Selection Guide
845D —S J D Z 1 4 B D CK 4
a b c d e f g h i
a
NEMA Rating
Code Description
JNEMA 4
XNEMA 4X Ê
ÊA
vailable with square flange
mounting configuration only
.
b
Mounting ConfigurationË
Code Description
DSquare Flange
E70mm Diameter Flange
F90mm Diameter Flange
GMetric Servo 48mm B.C.
H
English Servo
JMetric Servo 42mm B.C.
c
Shaft Options Ë
Code Description
A6mm Diameter
B10mm Diameter
C1/4in Diameter
Z3/8in Diameter
K6mm w/Flat
L10mm w/Flat
M1/4in w/Flat
N3/8in w/Flat
Ë
Standard catalog numbers consist of
either English Mounting Configura-
tions with English Shaft Options or
Metric Mounting Configurations with
Metric Shaft Options.
d
Power Supply Options
Code Description
15V DC ±5%
28–24V DC Unregulated
e
Output Configuration
Code Description
45V DC TTL Compatible
5NPN Open Collector
24V DC Max.
f
Latch Options
Code Description
ANo Latch
BLatch (Sink Output
Module Compatible)
g
Output Code Type
Code Description
DBinary Coded Decimal
GGray Code Ì
NNatural Binary
Ì
This option not available with Latch
Options code: “B.”
Electrical Connections
Function
Pin Gray
Code
Natural
Binary
BCD (8421)
A G(0) 201
B G(1) 212
C G(2) 224
D G(3) 238
E G(4) 2410
F G(5) 2520
G G(6) 2640
H G(7) 2780
J G(8) 28100
K G(9) 29200
LMSB
Complement Not Used 400
h
Resolution
Code Description
CW
256
Í
Gr
a
y Code
DW
512
Í
Gr
a
y
Code
or
FW
1024
Í
or
Natural Binary
CK
360
Î
Binar
y
Coded
CN
1000
Î
Binary
Coded
Decimal
Í
These options not available with
Output Code T
ype code: “D.”
Î
These options not available with
Output Code T
ype code: “G” & “N.”
i
Connector Options
Code Description
1Axial Connector (End)
without Mate
2Radial Connector (Side)
without Mate
4Axial Connector (End)
with Mate
5Radial Connector (Side)
with Mate
Function
Pin
Gray Code
Natural
Binary
BCD (8421)
MNot Used Not Used 800
NNot Used Not Used Not Used
PNot Used Not Used Not Used
RNot Used Direction
Control
Direction
Control
SNot Used Not Used Not Used
TDC Return DC Return DC Return
UNot Used Latch
Control Latch Control
VDC+ Input DC+ Input DC+ Input
Bulletin
845D Optical Absolute Encoders
NEMA Type 4, Single-Turn, Size 25
Encoders
7–22
Dimensions—mm (inches)
52.40
(2.063)
26.21
(1.032)
English
Servo Mount
Square Flange Mount
Connector
PT02E14–19P
(023)
7.62 (0.300)
6.35 (0.25)
74.93
(2.95)
21.59/22.86
(0.85/.90)
58.42
(2.30)
31.75
(1.250) Dia.
52.40
(2.063)
10–32 UNC-2B X 4.6 (0.18) Deep
on a 47.6 (1.875) Dia. Bolt Circle,
3 Places—120
° Apart
26.21(1.032)
5 (0.21) Dia.—4 Mtg. Holes
66.5
(2.62) Sq.
Radial Mount
Connector
Axial Mount
Connector
7.62 (0.300)
See T
able Below
10–32 UNC-2B x 4.6 (0.18) Deep
on a 47.6 (1.875) Dia. Bolt Circle,
3 Places—120
° Apart
2.54
(0.100)
22.86/21.59(0.90/0.85)
2.54
(0.100)
58.67 (2.31) Dia.
74.93
(2.95)
31.75
(1.250) Dia.
Connector
PT02E14–19P (023)
58.42 (2.30)
65
(2.56) Dia.
Axial Mount
Connector
Radial Mount
Connector
See T
able Below
63.50
(2.50) Dia.
20.0
Metric Flange Mount
Connector
PT02E14–19P (023)
6.35
Radial
Mount
Connector
3.05
20.0
M4 x 5.0 Deep
on a 70.0 Dia.
Bolt Circle,
4 Places—90
°
Apart
M4 x 5.0 Deep on a
64.0 Dia. Bolt
Circle, 4
Places—90° Apart
79.7
70.0 Dia.
31.75 Dia.
20.0
79.7
31.75 Dia.
Axial Mount
Connector
Axial Mount
Connector
6.35
Radial
Mount
Connector
3.05
90.0 Dia.
Metric Servo Mount
Connector
PT02E14–19P (023)
74.93
M4 x 5.0 Deep on a
42.0 Dia. Bolt Circle
3 Places—120
° Apart
M3 x 5.0 Deep on a
48.0 Dia. Bolt Circle 3
Places—120° Apart
8.0
2.54
31.75 Dia.
63.50 Dia.
Axial Mount
Connector
Radial Mount
Connector
65.0 Dia.
58.67 Dia.
2.54
20.0
2.54
31.75 Dia.
63.50 Dia.
Axial Mount
Connector
Radial
Mount
Connector
74.93
65.0 Dia.
58.67 Dia.
2.54
8.0
58.42 58.42
See
Table
Below
See T
able Below
See Table
Below See T
able Below
58.42 58.42
Shaft Diameter Options
Code Shaft
Diameter
A or K 6mm +0.00mm, –0.013mm
B or L 10mm +0.00mm, –0.013mm
C or M 6.35(0.2499 ) +0.0000, –0.0005
Z or N 9.52 (0.3749) +0.0000, –0.0005
19.05
(0.75)
Shaft with Flat Option
A
Flat Dimensions
Code Dimension
“A”
K5.3mm (0.21in)
L9.1mm (0.36in)
M5.5mm (0.22in)
N8.6mm (0.34in)
Bulletin
845D Optical Absolute Encoders
NEMA Type 4, Single-Turn, Size 25
