Applied Motion 3540i User Manual

7/31/98

Hardware Manual

3540i

Programmable

Step Motor Driver

Copyright 1998

Applied Motion Products, Inc.

404 Westridge Drive Watsonville, CA 95076

Tel [phone] [phone] Fax [phone]

Connections

Mechanical Outline - Optional MMI

NOTE
If option board
not present, ensure
that jumper is
present on pins 7
& 8.

Out1+
Out1­Out2+
Out2­Out3+

Outputs *

Out3-

Motor
Connections

A

B

-

+-+

Power
Input

V

+-

12V- 42V DC

1.38

0.13

2.988

0.960

0.963

1.975

➝

➝
➝

➝

123

YES NO

456

789

0.425

SPACE BKSP ENTER

.0

* inputs and
outputs are opto
isolated and require
external power
supply to drive
them. Voltage
required 5-24 VDC

+

-

ccw

LIMITS

­cw

-2-

+

IN3

IN4

cw

ccw

JOG

Inputs *

IN2

IN1

COM

COM

COM

4.90

3.875
CENTERED

3.875
CENTERED

4.90

-19-

Technical Specifications

Amplifiers

Power Supply

Inputs

Outputs

Microstepping

Dual, MOSFET H-bridge, 3 state, pulse width modulated
switching at 20 kHz. 0.2 - 3.5 amps/phase output current,
software selectable. 147 watts maximum output power.
Automatic idle current reduction (software programmable),
reduces current to motor when idle. Minimum motor inductance
is 0.8 mH.

Accepts 12 - 42 VDC power supply. 3.5 amps typical max load.
7A maximum power on surge.

5 - 24V, optically isolated. 2200 ohms internal resistance. Can
be configured for sinking (NPN) or sourcing (PNP) signals.

Optically isolated. 24V, 100 mA max.

13 software selectable resolutions. Steps per revolution with

1.8º motor: 2000, 5000, 10000, 12800, 18000, 20000, 21600,
25000, 25400, 25600, 36000, 50000, 50800. Waveform: pure
sine.

Introduction

Thank you for selecting an Applied Motion Products motor control. We hope our
dedication to performance, quality and economy will make your motion control
project successful. If there's anything we can do to improve our products or help
you use them better, please call or fax. We'd like to hear from you. Our phone
number is [phone] or you can reach us by fax at (831) 761–6544.

Features

• Powerful, precise and efficient mosfet driver providing up to 3.5 amps per
phase and microstepping to 50,800 steps per revolution.

• Accepts 12 - 42 VDC power supply.

• Powerful, flexible, easy to use indexer.

• Connects by a simple cable to your PC for programming (cable included).

• Microsoft Windows-based software for easy set up and programming.

• Eight inputs for interacting with the user and other equipment.

• Three outputs for coordinating external equipment.

• All I/O is optically isolated, 5 - 24 V, sinking or sourcing signals. (Except
PC/MMI port which is ±12V RS-232.)

• Sturdy 1.5 x 3 x 5 inch metal chassis.

• Screw terminal connectors for motor, DC power and I/O signals

• Optional man machine interface (MMI) allows operator to enter distances,
speeds, loop counts and more.

Motion Update

Physical

Connectors

12800 Hz.

Constructed on black anodized aluminum chassis/heat sink.

1.5 x 3 x 5 inches overall. 12 oz. 0-70ºC ambient temp range.
Power LED. See page 17 for detailed drawing .

Power, motor: screw terminal block. Wire size: AWG 12 - 28.
I/O Signals: screw terminal block. Wire size: AWG 16 - 28.

-18-

Block Diagram

12 - 42 VDC

INPUT1
INPUT2
INPUT3
INPUT4

CW JOG/IN5

CCW JOG/IN6

CW LIMIT

CCW LIMIT

to PC/MMI

Optical

Isolation

Optical

Isolation

RS232

Internal

Logic

Supply

Si™

Microstepping

Indexer

Sequencer

-3-

eeprom

MOSFET

3 State

PWM

Power

Amplifier

Optical

Isolation

motor phase A

motor phase B

OUT1
OUT2
OUT3

Getting Started

Recommended Motors

To use your 3540i motor control, you will need the following:

✔ a power supply (see page 5 for help in choosing one).
✔ a compatible step motor (see page 17 fopr recommended motors)
✔ a small flat blade screwdriver for tightening the connectors - an Applied Motion

Products screwdriver suitable for this purpose is included with your drive.

✔ a personal computer running Windows 3.1, 95 or NT with a 9 pin serial

port (486 or better with 8 MB ram recommended)

✔ the Si Programmer™ software that came with your 3540i
✔ the programming cable that came with your 3540i
✔ Si Programmer™ manual

The sketch below shows where to find the important connection and adjustment
points. Please examine it now.

power connector

• DC power supply

• motor

mounting hole (1 of 6)

Motor Size Winding Max Torque Current
Number inches Connection oz-in Amps

5014-842 1.38 x 1.38 x 1.57 4 lead 19 1.0
HT17-068 1.65 x 1.65 x 1.30 parallel 23 1.0
HT17-071 1.65 x 1.65 x 1.54 parallel 30 1.25
HT17-075 1.65 x 1.65 x 1.85 parallel 40 1.7
5023-122 2.22 x 2.22 x 2.0 parallel 60 2.0
5023-123 2.22 x 2.22 x 3.0 parallel 100 2.5
5023-124 2.22 x 2.22 x 4.0 parallel 150 3.5
HT23-394 2.22 x 2.22 x 1.54 parallel 60 2.8
HT23-397 2.22 x 2.22 x 2.13 parallel 140 2.8
HT23-400 2.22 x 2.22 x 2.99 parallel 180 2.0
5034-348 3.38 x 3.38 x 2.50 parallel 130 3.5

Mechanical Outline - 3540i

0.150"

4x Ø.170

2.45"

1.50

pc/mmi
connector

power
LED

connector

• output1,2,3

Always use the blue & white Applied

Motion screwdriver with these

connectors. Larger screwdrivers may

remove the plastic dimples that

prevent the screws from falling out.

connector

• input 1,2,3,4

• jog cw

• jog ccw

• cw limit

• ccw limit

4.70

0.15

3.00

-17--4-

5.00

0.25

0.25

.875

4.70

2x SLOT
.170 WIDE
FULL R

Flush Mounting

When you remove the MMI from the shipping carton, you will notice that it has two
parts. The first is a fairly thin section that contains the keypad, display and some
circuit boards. The other part is thicker and contains the telephone jack and a cable
that connects to the keypad assembly.

When you flush mount the MMI in a
panel, only the thin section will stick

MMI
(rear section)

MMI
(front section
and gasket)

out from your panel - the large
portion mounts behind your panel.
You'll need to cut a precise section
from your panel. There is a
cardboard template in your box for
this purpose.

If you want the MMI to be dust proof and
watertight, you must place the black rubber

1

23

45
789

6

.0

SPACE BKS

➝

➝

YES NO

P

ENTER

➝

➝

panel

gasket between the thin part of the MMI and
your panel. Assemble the two halves using the
eight small screws.

Surface Mounting

An easier way to mount the MMI is to bolt the two halves together ahead of time,
using the eight small screws. If you want the MMI to be dust proof and watertight,
put the black rubber gasket between the two halves before screwing them together.

Then cut a hole in your panel for the cable
that runs between the MMI and the 3540i.
The hole must be at least 5/8" in

gasket
(included)

sealant (not included)

panel

diameter for the connector to fit
through. You will also need two holes
that line up with the big mounting
holes in the MMI. The mechanical
outline on page 19 shows the location
of the big mounting holes.

When you mount the MMI to your
panel, you will need to use some kind
of sealant to keep dust and liquid out.

1

23

456
789

.0

SPACE BKSP ENTER

➝

➝

YES NO

➝

➝

MMI

Silicone or latex caulking is okay, or you
can make your own gasket from a sheet of
compliant material like rubber or RTV.

-16-

Connecting the Power Supply

If you need information about choosing a power supply, please read Choosing a
Power Supply below. The PS430 from Applied Motion Products is a good supply

for this drive.

If your power supply does not have a fuse on the output or some kind of short
circuit current limiting feature you need to put a 4 amp fast acting fuse between the
drive and power supply. Install the fuse on the + power supply lead.

Connect the motor power supply as shown below. Use no smaller than 20 gauge
wire. Be careful not to reverse the wires. Reverse connection will destroy
your driver, void your warranty and generally wreck your day.

3540MO

DC Power

Supply

12-42 volts

4A fuse

+
–

+ VDC –

Choosing a Power Supply

We recommend using an Applied Motion Products PS430 power supply with this
drive. The PS430 provides 30 volts DC at 4 amps, as well as 500 mA of well
regulated 5 volt power for your logic circuits. It also has built-in fuses. If you do
not choose an A.M.P. supply, please follow the recommendations below.

Voltage

Chopper drives like the 3540i work by switching the voltage to the motor terminals
on and off while monitoring current to achieve a precise level of phase current. To
do this efficiently and silently, you’ll want to have a power supply with a voltage
rating at least five times that of the motor. Depending on how fast you want to run
the motor, you may need even more voltage than that. If you choose an
unregulated power supply, do not exceed 28 volts. This is because unregulated
supplies are rated at full load current. At lesser loads, like when the motor’s not
moving, the actual voltage can be up to 1.4 times the rated voltage. For smooth,
quiet operation, a lower voltage is better.

-5-

Current

The maximum supply current you could ever need is the sum of the two phase
currents. However, you will generally need a lot less than that, depending on the
motor type, voltage speed and load conditions. That's because the 3540i uses
switching amplifiers, converting a high voltage and low current into lower voltage
and higher current. The more the power supply voltage exceeds the motor voltage,
the less current you’ll need from the power supply. A motor running from a 24 volt
supply can be expected to draw only half the supply current that it would with a 12
volt supply.
We recommend the following selection procedure:

1. If you plan to use only a few drives, get a power supply with at least twice the
rated phase current of the motor.

2. If you are designing for mass production and must minimize cost, get one
power supply with more than twice the rated current of the motor. Install the motor
in the application and monitor the current coming out of the power supply and into
the drive at various motor loads. This will tell you how much current you really
need so you can design in a lower cost power supply. If you plan to use a
regulated power supply you may encounter a problem with current fold back. When
you first power up your drive, the full current of both motor phases will be drawn for
a few milliseconds while the stator field is being established. After that the
amplifiers start chopping and much less current is drawn from the power supply. If
your power supply thinks this initial surge is a short circuit it may “fold back” to a
lower voltage. Because of that, unregulated power supplies are better. They are
also less expensive.

Mounting the Drive

You can mount your drive on the wide or the narrow side of the chassis. If you
mount the drive on the wide side, use #6 screws through the four corner holes. For
narrow side mounting applications, you can use #6 screws in the two side holes.

The 3540i drive will dissipate heat better if you mount it on the narrow
side. Please use narrow side mounting whenever possible.

smooth flat surface

#6 screws

wide side mount narrow side mount

The amplifiers in the 3540i generate heat. To operate the drive continuously at
maximum power you may need additional heat sinking or forced air cooling.

Never use your drive in a space where there is no air flow or where
other devices cause the surrounding air to be more than 50˚ C. Don't
put the drive where it can get wet or where metal particles can get on
it.

Mounting the Optional MMI

There are two ways to mount the MMI in your application. No matter which method
you choose, you'll need to connect the MMI to your 3540i with the programming
cable. You will not, however, need the adapter plug. The MMI has the same
telephone style connector as the 3540i.

Depending on how you mount the MMI and cable in your application, you may find
that it is difficult to remove the cable from the back of the MMI. If this is the case,
and you need to reprogram the 3540i, you can use any telephone line cord as a
programming cable. They are available at most supermarkets and discount stores.
Please be careful not to lose the adapter plug that connects the telephone cord to
the COM port of your PC. The adapter is a custom made part and is only available
from Applied Motion.

-6- -15-

Microstepping

Most step motor drives offer a choice between full step and half step resolutions. In
full step mode, both motor phases are used all the time. Half stepping divides each
step into two smaller steps by alternating between both phases on and one phase
on.

Microstepping drives like the 3540i precisely control the amount of current in each
phase at each step position as a means of electronically subdividing the steps even
further. The 3540i offers a choice of 13 step resolutions. The highest setting
divides each full step into 254 microsteps, providing 50,800 steps per revolution

when using a 1.8° motor.

In addition to providing precise positioning and smooth motion, microstep drives
can be used for motion conversion between different units. The 25,400 step/rev
setting is provided as a means of converting motion from metric to english. (There
are 25.4 mm in an inch.) Other settings provide step angles that are decimal

degrees (36,000 steps/rev makes the motor take 0.01° steps.) Some settings are

used with lead screws. When the drive is set to 2000 steps/rev and used with a 5
pitch lead screw, you get .0001 inches/step.

Connecting the Motor

Never connect the motor to the driver when the power is on.

!

Secure any unused motor leads.
Never disconnect the motor while the power is on.
Never connect motor leads to ground or to a power supply.

You must now decide how to connect your
motor to the drive.

Four lead motors can only be connected
one way. Please follow the sketch at the
right.

A+

A–

Red

Blue

Yellow

4 Leads

4

lead

motor

White

B+ B–

The microstep resolution of the 3540i is set by the Si Programmer™ software.

-14-

Six lead motors can be connected in series or center tap. In series mode, motors
produce more torque at low speeds, but cannot run as fast as in the center tap
configuration. In series operation, the motor should be operated at 30% less than
the rated current to prevent overheating. Winding diagrams for both connection
methods are shown below.

Note: NC means not connected to anything.

Grn/Wht

A–

White

NC

Green

A+

Red

B–

6 Leads Series Connected 6 Leads Center Tap Connected

lead

motor

Black

NC

6

Red/

Wht

B+

A–

A+

NC

Grn/Wht

White

Green

Red

lead

motor

Black

6

Red/

Wht

NC

B+B–

-7-

Eight lead motors can also be connected in two ways: series and parallel. As
with six lead motors, series operation gives you more torque at low speeds and less
torque at high speeds. In series operation, the motor should be operated at 30%
less than the rated current to prevent overheating. The wiring diagrams for eight
lead motors are shown below.

Orange

A+

Org/Wht

8

Blk/Wht

lead

Blk/Wht

A–

Black

Red

8 Leads Series Connected 8 Leads Parallel Connected

motor

Red/

B+ B–

Wht

Yel/
Wht

A–

Yellow

A+

Org/

Wht

Orange

Black

Red

B+

Yel/
Wht

8

lead

motor

Red/Wht

Yel
low

B–

Connecting to the PC

Wiring Outputs

Before we discuss the output conditions, we need to talk about the circuitry. All
three 3540i outputs are optically isolated. That means that there is no electrical
connection between the indexer-drive and the output terminals. The signal is
transmitted to the output as light. What you "see" is a transistor (NPN type) that
closes, or conducts current, when the output is "low". When the output is high, the
transistor is open.

At power-up, the 3540i sets all three programmable outputs high (open circuit).

The maximum voltage between any pair of + and - output terminals is
24 volts DC. Never connect AC voltages to the 3540i output terminals.
Maximum current is 100 mA per output.

+5V

330Ω

OUT1+

OUT1–

Optoisolator

NEC PS2502

or equiv.

inside 3540i

3540i

Controller Chip

• Locate your computer within 6 feet of the 3540i.

• Your 3540i was shipped with a black adapter plug. It has a telephone style jack
at one end and a larger 9 pin connector at the other . Plug the large end into the
COM1 serial port of your PC. Secure the adapter with the screws on the sides. If
the COM1 port on your PC is already used by something else, you may use the
COM2 port for the 3540i. On some PCs, COM2 will have a 25 pin connector that
does not fit the black adapter plug. If this is the case, and you must use COM2, you
may have to purchase a 25 to 9 pin serial adapter at your local computer store.

• Your 3540i was also shipped with a 7 foot telephone line cord. Plug one end
into the adapter we just attached to your PC, and the other end into the RS232 jack
on your 3540i.

Never connect the 3540i to a telephone circuit. It uses the same
connectors and cords as telephones and modems, but the voltages are
not compatible.

Programming Note: Always apply power to 3540i after the Si™
Programmer software is running on your PC.

Schematic Diagram of 3540i Output Circuit

Since there is no electrical connection to the 3540i, you must provide the source of
current and voltage, typically from a power supply. You must also limit the current
to less than 100 mA so that the output transistor is not damaged. You would
normally use a resistor for this, but some loads (such as PLC inputs) limit the
current automatically.

The diagram below shows how to connect an 3540i output to an optically isolated
PLC input.

12-24 VDC

Power Supply

+ –

OUTPUT+

COMMON

PLC

3540i

OUTPUT-

-13--8-

INPUT

+

IN/JOG COM

3540i

5-24

VDC

MOTION+

MOTION–

SI-1 indexer

Connecting an Input to the SI-1 Motion Output

(Set SI-1 motion signal to "in position". SI-1 will trigger 3540i at end of each move.)

IN

-

Power

Supply

Jogging

Two of the 3540i input terminals are provided for jogging the motor. The inputs are
labeled "JOG CW" and "JOG CCW". Activating one of the inputs commands the
drive to move the motor at a pre-designated speed until the contact is opened. A
relay or mechanical switch can be used to activate the jog inputs. 5-24 volt circuitry
can also be used. The schematic diagram of the input circuit is shown below.

If you're using a switch or relay, wire one end to the JOG input and the other to the
power supply - terminal. Then connect the COM and power supply + terminals.

+

COM

3540i

5-24

VDC

+

NPN

Proximity

Sensor

–

+

PNP

Proximity

Sensor

–

IN

output

output

COM

IN

IN

COM

-

3540i

Power

Supply

3540i

OUT+

or MC8400

OUT–

Si5580, 7080i

Connecting an Si5580, 7080i or MC8400

(When output closes, 3540i input goes low.)

5-24

+

VDC

Power

Supply

Connecting an NPN Type Proximity Sensor to an 3540i Input

(When prox sensor activates, 3540i input goes low.)

5-24

-

+

VDC

Power

Supply

Connecting a PNP Type Proximity Sensor to an 3540i input

-

(When prox sensor activates, 3540i input goes low.)

+
5-24
VDC

SUPPLY

-

COM

2200

CWJOG

2200

CCWJOG

Limit Switches

The 3540i has two limit switch inputs, LIMIT CW and LIMIT CCW. By connecting
switches or sensors that are triggered by the motion of the motor or load, you can
force the 3540i to operate within certain limits. This is useful if a program error
could cause damage to your system by traveling too far.

The limit inputs are optically isolated. This allows you to choose a voltage for your
limit circuits of 5 to 24 volts DC. It also allows you to have long wires on limit
sensors that may be far from the 3540i with less risk of introducing noise to the
3540i. The schematic diagram of the limit input circuit is shown below.

inside 3540i

+5V +5V

10K

3540i

Controller

Chip

CW LIMIT+

CW LIMIT–
CCW LIMIT+
CCW LIMIT–

inside 3540i

2200

3
4
1
2

TLP621 or

NEC PS2501

-12-

-9-

Wiring a Limit Switch

You can use normally open or normally closed limit switches. Either way, wire
them as shown here.

CW LIMIT+

+
5-24
VDC

SUPPLY

-

CCW LIMIT+

CW LIMIT-

3540i

CCW LIMIT-

Limit Sensors

Some systems use active limit sensors that produce a voltage output rather than a
switch or relay closure. These devices must be wired differently than switches.

If your sensor has an open collector output or a sinking output, wire it like this:

CW LIMIT+

+

DC

Power

Supply

–

+

Limit

Sensor

–

output

CW LIMIT-

Wiring for Sinking or Open Collector Output

3540i

Wiring Inputs

The 3540i input circuits can be used with
sourcing or sinking signals, 5 to 24 volts.
This allows connection to TTL circuits,
PLCs, relays and mechanical switches.
Because the input circuits are isolated,
they require a source of power. If you are
connecting to a TTL circuit or to a PLC,
you should be able to get power from the
PLC or TTL power supply. If you are using
relays or mechanical switches, you will
need a 5 - 24 volt power supply. This also
applies if you are connecting the 3540i
inputs to another Si product from Applied

COM
COM
COM

IN1

IN2

IN3

IN4

CWJOG

CCWJOG

inside 3540i

2200

2200

2200

2200

2200

2200

Motion, like the SI-1 and Si-100 indexers
or the Si5580, 7080i and MC8400
indexer-drives.

Note: if current is flowing into or out of an 3540i input, the logic state of that input
is low. If no current is flowing, or the input is not connected, the logic state is high.

The diagrams on the following pages show how to connect 3540i inputs to various
devices.

If the sensor output goes low at the limit, select the option "closed." If the output is
open, or high voltage, choose "open."

Other sensors have sourcing outputs. That means that current can flow out of the
sensor output, but not into it. In that case, wire the sensor this way:

+

DC

Power

Supply

–

+

Proximity

Sensor

–

output

LIMIT+

3540i

LIMIT-

Wiring for Sourcing Output

If the sensor output goes high at the limit, choose the program option "closed." If
the output is low at the limit, select "open."

-10-

The maximum voltage that can be applied to an input terminal is 24
volts DC. Never apply AC voltage to an input terminal.

+

COM

5-24

VDC

Power

Supply

Use normally open momentary switch to trigger 3540i using Wait Input instruction.

Use single throw switch for parameter selection using If Input instruction.

-

Connecting an Input to a Switch or Relay

Use normally open momentary switch for jogging.

switch or relay

(closed=logic low)

3540i

IN

-11-

Instructions

P/N 1000-175

Page 1 of 4

4/8/99

Encoder & RS485 Option Board

for 3540i Programmable Step Motor Drive

404 Westridge Drive

Watsonville, CA 95076

[phone] • fax [phone]

www.applied-motion.com

Installation

1) remove jumper 2) press encoder board
onto 8 pin header

3) secure
encoder
board
with three
screws

4) set the jumper

Page 2 of 4

Connectors

RS232

connector

RS485

connector

encoder

connector

232

485

RS232 settingRS485 setting

232

485

RS232

To use the RS232 interface, connect
your drive using the RS232 cable &
adaptor provided with your 3540i
drive.

Set the jumper as shown above.

RS485

Page 3 of 4

Set the jumper as shown on page 2 of these instructions.

Our RS485 implementation is a multi-drop network with separate transmit and receive wires. One pair of wires must
connect the host computer's transmit signals to each drive's RX+ and RX- terminals. Another pair connects the TX+
and TX- drive terminals to the host computer's receive signals. A logic ground terminal is provided on each drive and
can be used to keep all drives at the same ground potential. This terminal connects internally to the DC power supply
return (V-), so if all the drives on the RS485 network are powered from the same supply it is not necessary to connect
the logic grounds. You should still connect one drive's GND terminal to the host computer ground.

Before wiring the
entire system, you'll need to connect each drive individually to the host computer so that a unique address can be
assigned to each drive.

Proceed as follows:

1. Connect the drive TX+ to the PC's RX+ terminal.

2. Connect the drive TX- to PC RX-.

3. Connect RX+ to TX+.

4. Connect RX- to TX-.

5. Connect GND to GND.

Apply power to the PC and start the
power to the drive. Press the Caps Lock key.

SiNet™ Setup

The drives only accept commands in uppercase.

software. Select the proper comm port (1,2,3 or 4) then apply

Type RV then press
ENTER. If the drive has power and is properly wired, it will respond with "RV=x". Where x is the firmware version of
your drive. If the drive responds, you're home free: the RS485 network is functioning.

Next, you must choose an address for this drive. Any of the "low ascii" characters (many of which appear above the
number keys on a PC keyboard) is acceptable: ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < > ? @

To find out what address is in the drive now, type DA then press enter. The drive will respond with DA=x, where x is the
address that was last stored. (For example, the response might be DA=@ or DA=!). To change the address, type DAy,
where y is the new address character, then press ENTER.

To test the new address, type yRV, then press ENTER. For example, if you set the address to % and want to test that,
type %RV. The drive should respond just as it does to RV, the global revision level request.

Once all the drives have been assigned unique addresses, you can proceed to wire the whole system together as shown
below.

to PC GND

to PC TX­to PC TX+
to PC RX-

to PC RX+

+TX- +RX- GND +TX- +RX- GND +TX- +RX- GND

Drive #1 Drive #2 Drive #3

Getting an RS485 adaptor for your PC

Model 117701 from Jameco Electronics (800-831-4242) works well. This adaptor is for
a 25 pin serial port. If you are like most people and have a 9 pin serial port on your PC,
you will also need to purchase Jameco cable 31721. Connect as follows:

adaptor drive

1 RX+
2 RX­3 TX­4 TX+

Set the switches for DCE and TxON,RxON

Don't forget to plug in the DC power adaptor
that comes with the unit.

Wiring the Encoder

Page 4 of 4

The 1000-175 option board is designed for use with single ended or
differential output quadrature encoders. Differential encoders are
recommended because they provide better noise immunity.

There is one restriction on your choice of encoder. The motor resolution must
be a multiple of the encoder resolution. Keep in mind that the drive uses "X4"
decoding of the encoder signals, so a 1000 line encoder produces 4000
counts per revolution.

+5V +CH1- +CH1- GND

Connecting a Single Ended Encoder

An excellent choice of encoders is the U.S. Digital E2-1000 series. That unit
has a 1000 line code wheel, which produces 4000 counts/rev at the drive.
That will work well with a motor resolution of 20000 step/rev, which is the
default setting. Simply set the encoder ratio (ER software command) at 5.

The U.S. Digital E2-500 series is also popular and provides 2000 counts/rev.
For the E2-500, set ER at 10.

+5V +CH1- +CH1- GND

Connecting a Differential Encoder

The sketches on the right show proper wiring for single ended and differential
encoders. Built-in "pull up" resistors are provided for "open collector" encoder
outputs. A +5VDC output is provided for powering the encoder. 100 mA is
available.

DS26C32

The schematic diagram of the encoder input circuitry is shown at the right.

Testing the Encoder

In the diagram above, we suggested that you connect the encoder A
channel to the drive's CH1 input, and the encoder B channel to CH2.
However, depending on how your motor is wired, this might cause the
encoder to count in the opposite direction as the motor. That's bad,
because encoder position tracking depends on the encoder counting up when the motor does.

DS26C32

Encoder Board Schematic

+5V
A+
A­B+
B­GND

+5VDC

+5V
A
B
GND

single

ended

encoder

differential

output

encoder

10K

CH1+

CH1-

CH2+

CH2-

The best way to test the encoder is:

1. Wire the motor, encoder, power supply, and PC. Connect only one drive for this test. (It makes no sense to wire the

others now, as we aren't certain about the encoder connections yet.)

2. Power up the computer and the drive.

3. Launch the SiNet™ Setup software.

4. Type "EP" then press enter. The drive will respond with "EP=" and some number, near 0. That's your power on

encoder position, in encoder counts.

5. If EP is not 0, type EP0 to make it so.

6. Type "SP" then press enter. The drive will send "SP=0". The motor position is 0 steps.

7. Type FL. The motor will move one revolution in the positive direction.

8. Type SP. The new motor position should be "SP=20000". You've moved 20000 steps, the power on default distance.

9. Type EP. The drive will tell you the new encoder position. If that position is negative, you must power down the drive

and switch the encoder A and B wires. (On a differential output encoder, swap A+ for B+ and A- for B-.)

10. Power up and try again.

11. Once you've gotten the encoder counting in the right direction, you'll need to set the encoder ratio (ER). ER is the

ratio of encoder counts to motor counts. If, after step 9, you got SP=20000 and EP=4000, the ratio is 5. Type ER5.

Note: the drive does not "remember" the ER setting when power is removed. You'll need to reset this parameter each
time power is applied to the drive. This is true of nearly all SiNet™ Command Language parameters. The only
parameters that can be committed to nonvolatile memory are power on current (PC), power up mode (PM) and RS485
address (DA).