BEI Sensors HMT25 User Manual

HMT25 Absolute Multi-Turn Encoder

The HMT25 geared

multi-turn encoder

provides absolute posi-

tion information over

multiple turns of the

input shaft. It keeps

track of the exact posi-

tion even during periods of power loss without the need for a battery backup. The

HMT25 series is capable of outputs up to 4096 counts per turn and can count up to

4096 turns—a total of 24 bits or 16,777,216 positions. Units are enclosed in a 2.5-

inch diameter sealed package to withstand rugged environments and they carry an

IP 66 environmental rating. These encoders meet the long travel and high resolution

requirements of robotics, rolling mills, rotary tables, cable winding, printing, convert-

ing and material handling systems.

The H25 Incremental Encoder is avail able with the following certification:

EN 55011 and EN 61000-6-2

Mechanical Specifications

Shaft Diameter: 0.375” (0.5” optional)
Flat on Shaft: 0.80” long x 0.030” deep
Shaft Loading: 40 lbs axial, 36 lbs radial (90 lbs axial

and 80 lbs radial with 0.5” shaft)

Shaft Runout: 0.0005 TIR at midpoint of shaft
Starting Torque at 25°C: 2.5 in-oz (max)
Bearings: Dual, preloaded, Class ABEC 7
Shaft Material: 416 stainless steel
Bearing Housing: Die cast aluminum with protective finish
Cover: Die cast aluminum

Bearing Life: 1 x 1010 at 10% rated load

Maximum RPM: 6,000 (see frequency response, below)

Moment of Inertia: 4.3 x 10-4 oz-in-sec

Weight: 16 oz nominal

2

Electrical Specifications

Code: Natural binary, gray code or SSI
Counts per Shaft Turn: 4096, 12 bits
Number of Turns: up to 4096, 12 bits
Supply Voltage: 5–28 VDC
Current Requirements: 130 mA typical + load, 250mA (max)
Voltage/Output: (See note 3)

28V/V: Line Driver, 5–28 VDC in, V
28V/5: Line Driver, 5–28 VDC in, V
28V/OC: Open Collector, 5–28 VDC in, OC
SSI: 5–28 VDCin/5V

Frequency Response: 100 kHz
Protection Level: Overvoltage, reverse voltage.

Outputs short-circuit protected (1 minute max)
Output Termination Pinouts: See Tables, back page

(see back page)

out

= Vin

out

= 5 VDC

out

out

Environmental Specifications

Enclosure Rating: IP66
Temperature: Operating, 0° to 70° C; Extended, -40° to +85°C;

Storage, -20° to 90° C (to -40° if extended range is called out)

Shock: 50 g’s 11 msec
Vibration: 5 to 2000 Hz @ 20 g’s (see special note back page)
Humidity: 98% Non-condensing

NOTES & TABLES: All notes and tables referred to in the text

can be found on the back of this page.

HMT25 Multi-Turn Encoder Ordering Options FOR ASSISTANCE CALL 800-350-2727

Use this diagram, working from left to right to construct your model number (example: HMT25D-SS-12X12GC-28V/V-CW-SM18/32).

All notes and tables referred to can be found on the back of thispage.

HMT25

TYPE:

Heavy Duty

Multi-trun

2.5 inch Dia.

HOUSING :

D = Square Flange

E = Servo mount

These commodities, technology or software if exported from the United States must be in accordance with the Bureau of Industry, and Security, Export Administration regulations. Diversion contrary to U.S law is prohibited.

FACE MOUNTS:

F1 = 3,10–32,1.875 BC

F4 = 3, 6–32, 2.00 BC

CONFIGURATION:

SS = Shaft Seal

Tel: [phone] | Fax: [phone]
7230 Hollister Ave., Goleta, CA 93117-2807 | www.beisensors.com

COUNTS PER TURN:

12 = 4096 counts

SHAFT SEAL

See note 2

X

NUMBER OF TURNS:

4 = 16 turns
8 = 256 turns
12 = 4096 turns

CODE TYPE:

GC = Gray Code

NB = Natural Binary

VOLTAGE/OUTPUT:

28V/V = 5–28V

28V/5 = 5–28V
28V/OC = 5–28V

S3 = SSI Compatible

DIRECTION OF COUNT:

CW = Clockwise increasing count

CCW = Counter clockwise

increasing count

in/out
in/5Vout
in/OCout

A1 = 4–20mA

A2 = 0–10V

OUTPUT

TERMINATION:

E = End

S = Side

CONNECTOR:

M18/32 = 32 pin

Parallel output
M18 = 10 pin

(A1, A2 and S3 only)

SPECIAL FEATURES:

S= Special features

specified on purchase

order (consult factory)

See note 4

Specification No. 02083-001 Rev.08-11

HMT25 Absolute Multi-Turn Encoder

Tables and Figures

HMT25 Output Terminations for Parallel Output

PIN FUNCTION

A T11 (MSB)

B T10

C T9

D T8

E T7

F T6

G T5

H T4

(1) Parallel output uses a MS3112E18-32P, 32 Pin connector on the encoder body (2) TXX = Turns
counts, FXX = Fine resolution counts

(2)

PIN FUNCTION

J T3

K T2

L T1

M T0 (LSB)

N F11 (MSB)

P F10

R F9

S F8

(2)

PIN FUNCTION

T F7

U F6

V F5

W F4

X F3

Y F2

Z F1

a F0 (LSB)

(2)

1

PIN FUNCTION

b N/C

c LATCH

DIR CONTROL

d

ENABLE (Option)

e

f N/C

g 0 V

h +V

j CASE GND

HMT25 Output Terminations for Optional 24 Bit SSI Ouput

TERM BOARD
FUNCTION CABlE CONNECTOR* (H38 & H40 ONlY)

H38 H40
DATA+ YEL A 4 1

DATA- WHT/YEL H 7 7

CLOCK+ BLU B 5 2

CLOCK- WHT/BLU I 8 8

DIRECTION OF COUNT ORN C 6 3

ENABLE (Optional) VIOLET E 9 —

RESET (Optional) WHT/ORN J 10 9

+V (SUPPLY VOLTAGE) RED D 3 4

0 V (CIRCUIT COMMON) BLK F 2 5

CASE GROUND GRN G 1 6

*Connector is an MS3102E18-1P, 10-pin connector on the encoder body and mates to an MS3106F18­1S connector or can be used with a standard cable/ connector assembly, BEI part 924-31186-18XX.
(Where XX = 10, 20, or 30 for a 10, 20 or 30 foot cable length.)

Direction of Count: The HMT25 comes standard with a Direction of Count bit. Normal operation is CW
increasing count when viewed from the shaft end. This pin is normally pulled HI internally. To reverse the count

(2)

direction, this pin must be pulled LO (Circuit Common). Optionally this can be designated as CCW increasing
count when HI, in which case LO will be CW increasing count.

Latch: Outputs are active and provide continuous information when this pin is HI. When this pin is pulled LO (Circuit
Common) the outputs are latched at the logic state that is present when the latch is applied and will stay latched until
this pin is no longer LO. This pin is pulled HI internally.

Enable (optional): This option allows the operator to momentarily deactivate the outputs from the encoder. This
may be useful in instances where the outputs from several different encoders must be sampled independently.
Output is active when this pin is HI. When pulled LO (Circuit Common) all outputs go to high impedance state (Tri­state) and are inactive until the LO state is removed. This pin is pulled HI internally. To order this option on the HMT25
make sure the model number has –S on the end, followed by the description, –S = output enable.

RESET (Optional): The Reset pin (Pin J) is normally HI and is pulled up internally to the positive supply volt­age.To activate the Reset function, Pin J must be pulled LO by connecting it to signal common for 1 second or
greater. This causes the present encoder position to be stored into non-volatile memory as an offset value and
the output of the encoder is then set to the value of “0”. The encoder will retain this offset even if the power
is turned off and on again. A new “0” position can be set by rotating the encoder shaft to a new position and
then activating the Reset pin again. To order this option for the HMT25, make sure the model number has –S
on the end followed by the description, –S = Reset.

24 Bit, SSI Compatible Output Timing

Notes

Dimensions

Special note on vibration testing:

Test profile is 0.3 g’s ramp to 20 g’s from 5 to 40 Hz and 20 g’s from 40 Hz to 2000 Hz.

Tel: [phone] | Fax: [phone]
7230 Hollister Ave., Goleta, CA 93117-2807 | www.beisensors.com

1. Mounting is usually done either using the
D-style square flange mount, E- or G-style servo
mounts, or one of the standard face mounts, F1
for example. Consult factory for additional face
mount options.

2.The shaft seal is recommended in virtually all
installations. The most common exceptions are
applications requiring a very low starting torque
or those requiring operation at both high tem­perature and high speed.

3. Output IC’s: Output IC’s are available as
either Line Driver (LD) or NPN Open Collector
(OC) types. Open Collectors require pull-up resis­tors, resulting in higher output source imped­ance (sink impedance is similar to that of line
drivers). In general, use of a Line Driver style
output is recommended. Line Drivers source or
sink current and their lower impedance mean
better noise immunity and faster switching
times. Warning: Do not connect any line driver
outputs directly to circuit common/OV, which
may damage the driver. Unused outputs should
be isolated and left floating. Our applications
specialists would be pleased to discuss your
system requirements and the compatibility of
your receiving electronics with Line Driver
type outputs.

28V/V: Multi-voltage Line Driver (7272*): 100
mA source/sink. Input voltage 5 to 28 VDC +/­5% standard (Note: V
TTL compatible when used with 5 volt supply.
Supply lines are protected against overvoltage to
60 volts and reverse voltage. Outputs are short
circuit protected for one minute. Supply current
is 120 mA typical (plus load current). This is

= Vin). This driver is

out

the recommended replacement for 3904R and
7406R open collector outputs with internal pullup
resistors. It is also a direct replacement for any
4469, 88C30, 8830 or 26LS31 line driver.

28V/5: Multi-voltage Line Driver (7272*): 100
mA source/sink. Input voltage 5 to 28 VDC +/­5% standard, internally regulated with 5V (TTL
compatible) logic out. Supply lines are protected
against overvoltage to 60 volts and reverse volt­age. Outputs are short circuit protected for one
minute. Supply current is 90 mA typical (plus
load current). Note: Limit encoder load to 2.5W
max at ambient. Example at 12 VDC: 2.5W/
(+12VDC minus +5VDC) = 357 mA total allowed
current. Consult factory for your specific require­ments.

28V/OC: NPN Open Collector (3904*, 7273*).
Current sink of 80 mA max. Current sourced
by external pull- up resistor. Output can be
pulled up to voltage other than supply voltage
(30 V max). Input voltage 5 to 28 VDC +/- 5%
standard. Supply current is 120 mA typical. This
replaces prior IC’s with designations of 3904,
7406, 3302, 681 and 689.

4. Special –S at the end of the model number is
used to define a variety of non-standard features
such as special shaft lengths, voltage options,
or special testing. Please consult the factory to
discuss your special requirements.

* Products manufactured prior to April 2007 used the line driver IC number instead

of voltage output in model number.