Elmo SERVO AMPLIFIER DBP User Manual

0

Rev 6/93

DBP - Rev 6/93

1

ELMO-WARRANTY PERFORMANCE

The warranty performance covers only ELMO's products and only the
elimination of problems that are due to manufacturing defects resulting in
impaired function, deficient workmanship or defective material. Specifically
excluded from warranty is the elimination of problems which are caused by
abuse, damage, neglect, overloading, wrong operation, unauthorized
manipulations etc.

The following maximum warranty period applies:

12 months from the time of operational startup but not later than 18 months
from shipment by the manufacturing plant.

Units repaired under warranty have to be treated as an entity. A breakdown
of the repair procedure (for instance of the repair of a unit into repair of
cards) is not permissible.

Damage claims, including consequential damages, which exceed the warranty
obligation will be rejected in all cases.

If any term or condition in this warranty performance shall be at variance
or inconsistent with any provision or condition (whether special or general)
contained or referred to in the Terms and Conditions of Sales set out at the
back of Elmo's Standard Acknowledge Form, than the later shall prevail and be
effective.

DBP - Rev 6/93

2

How to use this manual - Flow Chart

The DBP HARDWARE MANUAL will lead you toward a successful start-up of your
digital amplifier. Please review carefully the following flow chart and write
down the chapters that you have to follow in the right order. Only after
performing all the steps you may proceed to the software manual.

If you are a new user of the DBP, you better not skip chapters 1-4 which
will familiarize you with the product.

Familiar with the DBP ?

Panel (H) version or Rack (R)

w/o Elmo mother board ?

Read chapter 5.1
Terminals

Read chapter 6 - Installation

Read chapter 7.1 - Start-Up

Hall sensors with
optical encoder ?

Read 7.2

no

no

Rack (R) with Elmo mother board ? Elmo enclosure ?

Read chapter 5.2
Terminals

no

Resolver ?

Read 7.3

Read chapters

1,2,3,4

no

Read chapter 5.3
Terminals

DBP - Rev 6/93

Adding velocity loop ? Read Appendix B

Read chapter 8 - Applying power - Adjustments

Read chapter 9 - Summaries

yes

3

TABLE OF CONTENTS

1.Description .......................................................... 7

2. Type Designation ................................ ................... 8

3. Technical Specification ............................................ 9

3.1 Digital I/O specification ................................ ... 10

3.2 Analog input specification .................................. 13

3.3 Sensors specification ................................ ....... 14

3.3.1 Encoder ................................ ............. 14

3.3.2 Resolver ................................ ............ 14

3.4 Communication ............................................... 16

3.4.1 RS232 Configuration ................................. 16

3.4.2 RS485 Configuration ................................. 16

3.5 Battery backup .............................................. 16

3.6 Performance ................................ ................. 16

4. System Operation ................................ ................... 18

4.1 RS485 and Checksum Protocol ................................. 18

4.2 Current Control ............................................. 18

4.2.1 Current feedback, Current feedback multiplier (CFM) and

Current loop ................................ ............... 19

4.3 Digital current limits ................................ ...... 20

4.3.1 Time dependent peak current limit ................... 20

4.4 Digital position and speed control .......................... 21

4.5 Operation of the shunt regulator ............................ 25

4.6 Commutation signals format .................................. 26

4.7 Protective functions ................................ ........ 27

4.7.1 Short circuit protection ............................ 27

4.7.2 Under/over voltage protection ....................... 27

4.7.3 Temperature protection .............................. 27

4.7.4 Internal power supply failure ....................... 27

4.7.5 Loss of commutation feedback ........................ 27

4.7.6 Low back-up Battery voltage ......................... 27

5. Terminal Description ................................ ............... 33

5.1 Terminals for Horizontal and Rack mounting versions ......... 33

5.2 Mother Boards terminals (MBA-DBP/3U and MBA-DBP/6U) ......... 43

5.3 Terminals for DBP mounted in ENCD. .......................... 54

5.4 Communication Port Connector ................................ 64

DBP - Rev 6/93

4

6. Installation procedures ............................................65

6.1 Mounting.....................................................65

6.2 Wiring....................................................... 65

6.3 Load inductance................................ ..............66

6.4 AC power supply................................ ..............66

6.5 Wiring diagrams................................ ..............67

6.5.1 Motor's windings ................................ .....67

6.5.2 AC power wiring ................................ ......68

6.5.3 Hall sensors wiring ................................ ..77

6.5.4 RS232 Communication wiring ...........................78

6.5.5 RS485 Communication wiring ...........................79

6.5.6 Main encoder wiring ................................ ..81

6.5.7 Resolver wiring ................................ ......82

6.5.8 Auxiliary encoder wiring .............................83

6.5.9 Pulse/Direction signals wiring .......................84

7. Start - Up Procedures .............................................. 85

7.1 Common procedures for all amplifiers types ...................85

7.1.1 Commutation signals format ...........................85

7.1.2 CFM function ................................ .........85

7.1.3 Abort logic ................................ ..........85

7.1.4 Setting the auxiliary position input format ..........86

7.1.5 Selecting the communication bus ......................86

7.1.6 Preparing the automatic baud rate selection ..........86

7.2 Setting the main optical encoder format ......................87

7.3 Setting the R/D circuit......................................87

8. Applying power - Adjustments ................................ .......94

Step 1 - Applying Power ................................ .....94

Step 2 - Establishing the communication .....................95

Step 3 - Checking the feedback elements .....................95

Step 4 - Adjusting the current limits .......................95

Step 5 - Latch mode of the protective functions .............96

Step 6 - Connecting the Motor ...............................96

9. Tables and Summaries ............................................... 97

9.1 Display diagnostics................................ ..........97

9.2 Summary of DIP switches......................................98

Appendix A - Current loop response ................................ .....99

DBP - Rev 6/93

5

Appendix B - Adding a velocity feedback ............................... 101

Appendix C - Differential amplifier connection ........................ 102

DIMENSIONAL DRAWINGS ................................ ................... 103

PANEL (H), DBP1 ................................ .................. 104

PANEL (H), DBP2 ................................ .................. 107

PANEL (H), DBP3 ................................ .................. 110

PANEL (H), DBP4 ................................ .................. 113

PANEL (H), DBP6 ................................ .................. 116

RACK 3U/13T ................................ ...................... 119

RACK 3U/20T ................................ ...................... 122

RACK 6U/14T ................................ ...................... 125

RACK 6U/21T ................................ ...................... 128

ENCD - 3U/... ................................ .................... 130

ENCD - 6U/... ................................ .................... 131

EXTERNAL SHUNT RESISTOR ................................ .......... 132

List of ELMO Service Centers ........................................... 133

DBP - Rev 6/93

6

1.Description

The DBP series are digital, full wave, three phase servo amplifiers designed
for high performance brushless servo motors in the range of up to 7KW. They
utilize power MOSFETs and Surface Mounting Technology which contribute to its
high efficiency and compact design. The DBP operates from a single AC supply
(either single or three phase) and, when using the galvanic isolation option,
it can be connected directly to the Mains.

The DBP is constructed from two main PCBs mounted on a heat sink plate. The
lower board contains the rectifying bridge, the power switching transistors
which drive the motor, terminals for the power stage, the switch mode power
supply, the protection logic and commutation logic. The upper PCB is the
Digital Control Board (DCB) which contains the digital control logic, terminals
for the control stage, D-type connector for the communication and a 4-digit
display.

The DBP requires a position sensor in order to enable its operation. It can
be either a Resolver or a combination of an optical encoder and Hall effect
sensors. When using a Resolver, a small interface card is mounted on top of the
DCB.

The DBP is available in either panel version or rack version with two DIN
41612 connectors. The rack version can be fitted in a panel mount enclosure
(ENCD-3U or ENCD-6U), that is specially designed for a simple hook-up
procedure.

The amplifiers are fully protected against the following faults:

* Under/over voltage
* Shorts between the outputs or between the outputs to ground.
* RMS current limit.
* Insufficient load inductance.
* Loss of commutation signals.
* Excess temperature.
* Excess position error.

Analog Section Standard Features:

* Single AC supply (single or three phase)
* Zero Deadband.
* Motor current monitor.
* Motor speed monitor.
* Extra differential operational amplifier.

DBP - Rev 6/93

7

DBP F- 24 / 270 R R O

* Standard commutation sensors: Hall effect sensors or a Resolver.
* Galvanic isolation of the control stage - option.

Digital Section Standard Features

* Accepts motion commands via RS232 or RS485
* Buffering for pipe lining instructions prior to execution
* Battery-backed RAM for storing user programs and parameters
* Conditional statements for controlling program execution real- time.
* Programmable time and position trip points
* Variables for entering and changing system parameters
* 5 Uncommitted inputs
* 2 uncommitted high speed inputs.
* 10 Uncommitted outputs
* Arithmetic and logic functions for manipulating parameters
* Digital filter with programmable gain, damping and integrator
* Error handling, end of travel, emergency stop, status reporting.
* 0-600,000 quadrature counts/second speed range
* One analog input - 11 bit resolution
* Master/slave operation with programmable following ratio (master information

from an optical encoder or from Pulse and Direction inputs)
* Dual-loop capability
* Adjustable continuous and peak current limits
* 4-digit display for diagnostics.

2. Type Designation

DBP series amplifier

Fan cooling required for full rating

Rated continuos current

Max. operating AC voltage

I - Isolation *

O - Off line:

Isolation + Inrush current limit

E - Optical encoder + Hall sensors
R - Resolver

R - Rack mounting

H - Panel mounting

DBP - Rev 6/93

3. Technical Specification

8

Type AC Supply

min max

*

Current
limits

Size
Panel(H)

Size
Rack(R)

Weight

(Kg)
DBP-12/135 28- 135 12/24 DBP2 3U/20T 1.4
DBP-20/135 28- 135 20/40 DBP3 6U/21T 3
DBP- 8/270 100- 270 8/16 DBP2 3U/20T 1.4
DBP-16/270 100- 270 16/32 DBP3 6U/21T 3

DBPF-12/135 28- 135 12/24 DBP1 3U/13T 0.7
DBPF-20/135 28- 135 20/40 DBP4 6U/13T 1.3
DBPF-30/135 28- 135 30/60 DBP6 6U/21T 3
DBPF- 8/270 100- 270 8/16 DBP1 3U/13T 0.7
DBPF-16/270 100- 270 16/32 DBP4 6U/13T 1.3
DBPF-24/270 100- 270 24/48 DBP6 6U/21T 3

*

These are the absolute minimum-maximum AC supply voltage under any condition.

DBP - Rev 6/93

9

General

* DC output voltage is 130% of AC input voltage.
* 2KHz current loop response
* Outputs voltages of +5V/0.2A, +15V/0.1A for external use.
* Efficiency at rated current - 97%.
* Operating temperature: 0 - 50°C.
* Storage temperature: -10 - +70°C.

3.1 Digital I/O specification

Digital Inputs:

High/Low input definition: Vil<1V, Vih>2.4V
Maximum input voltage: 30V
Input impedance: 3-7Kohm
Input hysteresis: typ 1V.
When left open: low level.
Input threshold level can be shifted on request.
The fast inputs capture events (input voltage level
going from low to high) of less then 10 µsec duration.

Digital Outputs:

High/Low output definition: Vol<0.4V, Voh>4V
Output level: 0-5V
Recommended output current: Iol=Ioh=5mA
Maximum output current +10mA
The outputs are normally at low level.

DBP - Rev 6/93

10

U17

Q0

D0

Q1

D1

Q2

D2

Q3

D3

Q4

D4

Q5

D5

Q6

D6

Q7

D7

VCC

OC

74HCT373A

2
5
6
9
12
15
16
19

+5V

20

3 2

U11A
74HCT4050

5 4

13b

14b

15b

16b

17b

OUT 1

OUT 2

OUT 3

OUT 4

OUT 5

1b

2b

3b

5a

OUT 6

OUT 7

OUT 8

OUT9

6a

OUT10

U11B
74HCT4050

7 6

U11C

7a

MOTION
COMPLETE

74HCT4050

DIGITAL OUTPUTS

DBP - Rev 6/93

11

FORWARD

LIMIT SWITCH

REVERSE

LIMIT SWITCH

HOME INPUT

ABORT INPUT

9a

10a

12a

13a

18b

I1

I2

I3

I4

19b

20b

21b

1 3

4 6

SN75C189AD

10 8

13 11

1 3

4 6

10 8

13 11

U100A
SN75C189AD

U100B

U100C

SN75C189AD

U100D

SN75C189AD

U102A
SN75C189AD

U102B

SN75C189AD

U102C

SN75C189AD

U102D

SN75C189AD

DBP - Rev 6/93

I5

22b

1 3

INDEX SLAVE

I6

15a

16a

I7

4 6

10 8

DIGITAL INPUTS

U103A
SN75C189AD

U103B

SN75C189AD

U103C

SN75C189AD

12

3.2 Analog input specification

Maximum input voltage:

- When R1 (470ohm) is inserted, the absolute value of the input voltage should be

less than 5V.

- When the absolute value is higher than 5V, R1(Kohm) = 2Vi-10 should be inserted.
The µP reads always +5V.

Resolution of the digital conversion: 11 bit full scale.

Typical offset: 5 bits

470K

VREF

4700PF

VREF

300

4700PF 4700PF

300

4700PF

DIGITAL GND

U1\10

U1\11

ANALOG
INPUT

18a

R1

*

1 2

10K

DIGITAL GND

470k

6
5

U8B

DIGITAL GND

7

470k

470k

9
10

DIGITAL GND

20K

4700PF

8

U8C

1000PF

20K

13
12

U8D

DIGITAL GND

14

DBP - Rev 6/93

ANALOG INPUT

13

3.3 Sensors specification

3.3.1 Encoder

The encoder must be incremental with two TTL channels in quadrature and 90 °
phase shift.
High/Low input definition: Vil<1.5V, Vih>3V
Input voltage range: 0-15V
Input hysteresis 1.5V
Input impedance: 1Kohm to 5V.
Maximum frequency main encoder: 150KHz
Maximum frequency auxiliary encoder: 250KHz
Noise protection by analog and digital filters
When left open the input is internally pulled to high level.

3.3.2 Resolver

Resolver Option Feature:

* 10,12,14 and 16 bit resolution set by the user.
* Maximum tracking rate 1040 rps (10 bits).
* Velocity output.
* Encoder A, B, outputs + programmable index output.

Reference parameters:

Max. voltage: 20Vptp or 7Vrms
Minimum output voltage: 2Vrms
Max. current: 80mA
Max frequency: 20KHz outputs:

DBP - Rev 6/93

CH B

CH B

27a

*

R705

28a

1000P

100

100

+5v+5v

1K
1000P

DS3

+5v

14

+5v

1K

100K

+5V

1K

3
2

7

U105

301K

Vref

CH A

CH A

AY/PULSE

AY/PULSE

INDEX

INDEX

29a

30a

21a

22a

31a

32a

*

R704

*

*

R707

R708

100

100

1000P

100

100

1000P

100

100

1000P

+5v

+5v +5v

+5v +5v

+5v

1K
1000P

1K

1000P

1K
1000P

DS5

+5v+5v

+5v

DS6

+5v+5v

DS2

1K

+5v

1K

1K

100K

100K

100K 11

10

+5v

1K

3
2

3
2

301K

301K

301K

U104

U107

13

U31D

7

+5v

2.49K

7

+5V

1K

4
5 6U121B

REMARK:

R704 - 708 ARE NOT INSTALLED IN FACTORY STANDARD SETTING.

DBP - Rev 6/93

BY/DIR

BY/DIR

23a

24a

+5v +5v

+5v

1000P

100

R706*

100

1K

DS4

1000P

+5v

1K

3
2

100K

301K

ENCODER INPUTS

+5v

2.49K

7

U106

15

3.4 Communication

3.4.1 RS232 Configuration

The RS232 is configured for 8-bit, no parity, full duplex and it will echo all
the transmissions.
Baud rates: 300,600,1200,2400,4800,9600,19200,38400,57600
No hardware handshaking is required.

3.4.2 RS485 Configuration

The RS485 is configured for 8-bit, no parity, half duplex.
Baud rates: 300,600,1200,2400,4800,9600,19200,38400,57600
No hardware handshaking is required.

3.5 Battery backup

180mAH battery that at rated operating and storage condition will last for

at least 40,000 non operating hours.

3.6 Performance

Position range: +230 quadrature counts
Velocity range: +600,000 counts/sec
Velocity resolution: 1 count/s
Acceleration range: 91 - 11.8x106 count/s
Acceleration resolution: 91 counts/s

2

DBP - Rev 6/93

16

RS232

DZ13v

TRANSMIT
RECEIVE
GND

RS485

T/R-

T/R+

TRANSMIT/
RECEIVE CONTROL

+5V

3
2
5

6

7

8

9

1

4

-15V

120

ohm

1K

300

0.1MF

* R802

*

+5v

R119

U115

1

-V

7

DY

5

RA

4

GND

SN75155

0.1MF
U114

8

VCC

7

B

6

A

5

GND

SN75LS176

+5v

RE
DE

DA

RY

RTC

R

D

+15V

300

DZ13v

0.1MF

8

+V

2
3
6

+5v

DS9

RS232-OFF
RS485-ON

RS485/RS232

1
2
3
4

1K

Notes:

R119 - LINE TERMINATION RESISTOR, USED ON BOTH ENDS OF LONG LINES. NORMALLY NOT MOUNTED.

*
* R802 - SMD RESISTOR. NORMALLY NOT MOUNTED

DBP - Rev 6/93

COMMUNICATION

17

4. System Operation

4.1 RS485 and Checksum Protocol

The RS485 in the DCB is configured as 8-bit, no parity, 1 stop bit, half
duplex. The following baud rates are available: 300, 600, 1200, 2400, 4800,
9600, 19200, 38400, 57600. No hardware handshaking is required.

In the RS-485, which is a Half Duplex system, all the Transmitters and all
the Receivers share the same Multidrop wire. Therefore, each character that is
transmitted on the line, is automatically received by all the Receivers. This
is an inherently "confused" way to transmit data and no "Echo" procedure can
assure reliable communication.

In order to solve this reliability problem, it is necessary to use standard
protocols procedures.

It is important to understand that using RS485 with the DCB products without
any protocol is possible. This is also the default condition whenever the RS485
is activated. However, the reliability of the communication is only assured
when activating the protocol. This is done by sending the command CK1 from the
host to the DCB.

Chapter 1.2.1 in the DCB Software manual explains the standard protocol used
and supplied by Elmo.

4.2 Current Control

The analog part of the DBP is actually a standard amplifier that operates in
current mode. However, the DCB receives continuously analog information about
the current magnitude, direction and ripple. This information is processed to
obtain digital control of the following features:

* Continuous current limit
* Peak current limit
* Time dependent peak current limit
* Current ripple

DBP - Rev 6/93

18

4.2.1 Current feedback, Current feedback multiplier (CFM) and
Current loop

Three current feedbacks are obtained by measuring the voltage drop across
current sensing resistors or by current transformers (when using the isolation
option). These three signals are synthesized and multiplexed which result in a
single voltage signal proportional to phases currents. It is then compared to
the current command. The error is processed by the current amplifier to provide
a voltage command to the PWM section.

Current loop control is obtained by op amp U21/A (current amplifier) and R4,
C1 which form a lag-lead network for current loop. The standard amp is equipped
with R4 and C1 to get optimum current response for an average motor in this
power range. These components are mounted in solderless terminals.

Error amplifier Current amplifier

x2

Current feedback

CFM

The amplifier is equipped with a Current Feedback Multiplier (CFM). By
turning DIP switch 2 (on the upper board of the power stage) to ON, the signal
of the current feedback is multiplied by 2 and consequently the following
changes occur:

- Current gains are multiplied by 2.

- Current monitor is divided by 2.

- Current limits are divided by 2.

- Dynamic range is improved.

- Commutation ripple is reduced.

DBP - Rev 6/93

19

This function should be activated whenever the rated current AND the peak
current of the motor are less than 20% of the amplifier rated continuous and
peak limits respectively.

Sometimes, oscillations may occur in the current loop due to the fact that
the feedback gain was multiplied. This can be resolved by substituting R4 with
a lower value.

4.3 Digital current limits

The servo amplifier can operate in the following voltage-current plane:

+V

-Ip -Ic

Intermittent
zone

Ic - Continuous current Ip - Peak current

Each amplifier is factory adjusted to have this shape of voltage-current
operating area with rated values of continuous and peak current limits. By
using the command CL(n) for the continuous and PL(n) for the peak it is
possible to adjust the current limits (continuous and peak independently) from
the rated values down to 10% of the rated values.

Continuous
zone -V

Fig. 4.1: Voltage-Current plane

Ic Ip

4.3.1 Time dependent peak current limit

The peak current duration is a programmable parameter which is also a
function of the peak amplitude and the motor operating current before the peak
demand. The user defines the maximum duration of the full amplitude peak by the
instruction PDn - n cannot be more than 2 seconds. In addition to this
definition, a digital filter is employed to ensure that the RMS value of the
current will not exceed the continuous current limit. The duration of Ip is
given by:

DBP - Rev 6/93

20

Ip - Iop
Tp = 2.2ln ---------­ Ip - Ic

Iop - Actual operating current before the peak demand.

The result of this filter is that the maximum peak can last for a maximum of

2 seconds. A lower peak can last longer.

Example: A motor is driven by an DBPF-10/135 amplifier at constant speed and
constant current of 5A. What is the maximum possible duration of a 20A peak ?

20 - 5
Tp = 2.2ln -------- = 0.892 seconds
20 - 10

4.4 Digital position and speed control

The DCB accepts motion commands via an RS232 or RS485 communication line and
receives position feedback in an incremental encoder format either from an
encoder or from the resolver/digital circuit. The DCB derives the closed-loop
position error by comparing the command position and the feedback position. The
error is processed by a digital filter to yield with an analog motor command.
The analog +5 volt range motor command is then amplified by the power
amplifier.

Following is a summary of all the operating modes of the DCB and a detailed
discussion of each of them.

Control Modes
Holding Modes.
Start Modes
Program Mode
Termination Modes
Status reporting
Define origin modes

DBP - Rev 6/93

21

Control Modes

The DCB can be commanded to control the position of a motor, its torque or

its velocity using three basic control modes:

- Position Mode

- Velocity Mode

- Position Follower Mode

Position Mode

In the position mode the motor will advance a specified distance and then
stop. This distance can be represented as an absolute position (PA n) or as a
relative distance from the current position (PR n). The motion will follow a
trapezoidal or triangular profile with the acceleration (AC n) and slew
velocity (SP n) set by the user.

Velocity Mode

In the velocity mode the motor will accelerate to a specified slew speed. It
will hold this speed until a stop condition is received (see termination
modes), or a new velocity/direction is commanded.

Position Follower

It can also control the motor as a position follower of a master encoder or
a pulse and direction signals.

Holding Modes.

The holding modes describe the behavior of the system after it has stopped.
There are three holding modes:

- Servo

- Motor Off

Servo Mode

In the servo mode (SV) the system maintains stopping position by using its
control law to correct for any position errors.

Motor Off Mode

In the Motor Off mode is, the power bridge and the position control are shut
off and there no torque is generated by the amplifier. The Motor Off mode is
useful in robotics applications in the teaching mode.

DBP - Rev 6/93

22

Start Modes

There are three start modes to begin a move:

Direct command

A move can be initiated directly by a command from the host or a terminal.

Program

A move can be initiated by a command included in the user program.

Input condition

Another alternative is to have the move started by a conditional statement

specified by the user program.

Program Mode

A set of commands can be implemented as a user program to allow for
automatic and/or complex types of moves. The user may specify software
variables, conditional statements, subroutines and error routines which enable
enhanced motion control.

Termination Modes

A motion can be terminated in a variety of ways. In all but emergency
termination modes the motor will be decelerated gradually to a stop and then
will enter one of the stationary modes (Servo, or Motor Off). In a position
mode move, the motion will terminate naturally upon reaching the desired final
position. In all of the control modes the motion can be terminated by a command
from the host. An additional means of termination is from one of the local
inputs.

Activating the forward and reverse limit switch inputs can be another means
of terminating a move. Upon contacting the switch, the #[ routine will be
activated. This is a user programmed routine that should normally include a
stop command to decelerate the motor to a full stop.

There are two methods of generating an emergency stop. The first is by an
abort command from the host, and the other is by the local abort input. Upon
receipt of either of these commands the system will go immediately to its
stationary mode.

Another "unnatural" way to terminate a motion is whenever an internal
amplifier inhibit (due to one of the protections) occurs. This turns off the
power stage and the motor will decelerate to a stop by friction only. There are
two modes of handling the internal amplifier inhibit:

Latch Mode

The power stage is disabled and only a reset will release it.

DBP - Rev 6/93

23

Auto restart

The power stage inhibit will automatically be released upon clearing the

cause of the inhibit.

Status Reporting

Status is available to the user in several ways.

Communication

In response to the Tell Status command (TS) the DCB sends a coded message

describing the status of the amplifier.

In addition, the host may request certain information at any time. This
consists of the state of the system (GN?, ZR?, PL?, KI?), the state of the
local inputs (TI), the torque level (TT), the current motor position (TP), the
current motor velocity (TV) and the reason for a stop condition (TC).

Refer to the DCB Software Manual for further details.

Hardware signal

Motion complete signal

This output will go to high when motion is complete.

Inhibit output

Whenever the amplifier is inhibited, this open collector output goes to low.
When using Elmo's mother boards a potential free relay replaces the open
collector output.

4-digit display

Whenever a fault occurs, a fault message will be displayed for easy visual
information. See chapter 9.1 for a summary of all amplifier's fault
indications.

Define origin modes

The origin is that location at which the absolute position of the motor
equals zero. This special location may be defined in two ways. First, the user
may send a command (DH) which defines the current motor position to be the
origin. The alternate method is to request the DCB to perform the homing
sequence by commanding HM.

DBP - Rev 6/93

24

4.5 Operation of the shunt regulator

A shunt regulator is included in the power supply section of the DBP. The
shunt regulator is a switching type, wherein dissipative elements (resistors)
are switched across the DC bus, whenever the voltage reaches a predetermined
level (Vr). The function of the shunt regulator is to regulate the voltage of
the DC bus during the period of motor deceleration, when there is a net energy
outflow from the motor to the amplifier. The amplifier handles this reverse
energy just as efficiently as it provides energy to the motor, hence, most of
the energy is passed through the amplifier to the power supply, where the
returning energy charges the filter capacitors above their normal voltage
level, as determined by the AC incoming voltage.

When the capacitors charge-up reaches the predetermined voltage level (Vr),
the shunt regulator begins its regulating action. The bus is regulated to this
range until regeneration ceases.

All the double Eurocard size amplifiers are equipped with two outputs for
connecting an external shunt resistor , hence increasing the power dissipation
capability.

SHUNT specifications

Type Reg.

Voltage

(Vr)
DBP-12/135 193 13 N/A
DBP-20/135 193 26 21
DBP-8/270 383 8 N/A
DBP-16/270 383 16 12
DBPF-12/135 193 13 N/A
DBPF-20/135 193 26 N/A
DBPF-30/135 193 26 21
DBPF-8/270 383 8 N/A
DBPF-16/270 383 16 12
DBPF-24/270 383 16 12

Internal
Reg.
Current (A)

External Reg.
Current (A)

DBP - Rev 6/93

4.6 Commutation signals format

A

B

C

25

60 FORMAT (120)

300

A

B

C

0

300

+

-

Vac

(360)

(360)

60 120 180 240 300 360 600

(0)

30 FORMAT

60 120 180 240 300 360 600

(0)

+

Vba

0

-

Vcb

+

0

-

300

(360)

DBP - Rev 6/93

MOTOR BEMF

60 120 180 240 300 360 600

(0)

26

4.7 Protective functions

All the protective functions except "Low Back-up Battery Voltage" activate
an interrupt to the main processor which inhibits the power bridge and disable
current flow to or from the motor. The user can interrogate the processor in
order to verify the cause of the inhibit. An indication of the fault will
appear on the display. The following protections are processed by the DCB:

4.7.1 Short circuit protection

The amplifier is protected against shorts between outputs, or either output
to ground, or either output to the positive supply line.

4.7.2 Under/over voltage protection

Whenever the DC bus voltage is under or over the limits indicated in the
technical specifications, the amplifier will be inhibited.

4.7.3 Temperature protection

Temperature sensor is mounted on the heatsink. If, for any reason, the
temperature exceeds 85°C the amplifier will be inhibited. The amplifier will
restart when the temperature drops below 80 °C. The user can always interrogate
the DCB about the heatsink temperature by using the command T?.

4.7.4 Internal power supply failure

In any case that the sum of the internal power supplies is below 13V or its
difference higher than 1V, the amplifier will be inhibited.

4.7.5 Loss of commutation feedback

Lack of either of the commutation signals will inhibit the amplifier.

4.7.6 Low back-up Battery voltage

When the battery voltage goes below 2.4V the DCB will send a message on the
communication line and will display "BATT" on the display.

DBP - Rev 6/93

+VS

27

MOTOR OUTPUTS

AC
AC
AC

CONTROL

HA
HB
HC

RECTIFING,
CURRENT
INRUSH LIMIT

POWER
COMMON

SUPPLIES

PWM SIGNAL
PROTECTIONS
CURRENT FEED BACK

SHUNT
CONTROL

SMPS

ISOLATION

"HALL" SIGNAL

PROCESSING

D1 D2 D3

D4

SUPPLIES

PWM SIGNALS
PROTECTIONS
CURRENT FEED BACK
"HALLS" SIGNALS

CURRENT SENSING

D1 D2 D3 D4

COMMUTATION

CURRENT PROCESSING

D6D5

D5 D6

DBP - Rev 6/93

DBP 3U - BLOCK DIAGRAM

Display

28

RS232
RS485

Outputs
Buffers

Inputs
Buffer

Aux
Encoder
Buffer

Analog in

Encoder

MOTOR COMMAND

VELOCITY/ CURRENT MODE

TO POSITION

PROCESSOR

ENCODER OUTPUTS

Master
Processor

Position
ProcessorBuffer

MEMORY

SHORT SIGNAL
UNDER / OVER - SIGNAL
TEMP SIGNAL

Current
limits

CURRENT

AMPLIFIER

100K
R4

BATTERY

BACK UP

POWER

STAGE

Current
Feedback

PWM

A

.01UF

C1

RESOLVER

OPTION

VELOCITY
FEEDBACK

SIGNAL

TACH INPUT (OPTION)

(TACH OUTPUT WITH RESOLVER OPTION)

R2

R3

INH. OUT 10MA/30V

10K

10K

­+

1K

R800

100K
option

R6

OFFSET
OPTION

100K

R7

C2

+V

1M

-V

100K

10K

100K

ERROR

R5

A

option

619K

100K

AMPLIFIER

DCB BLOCK DIAGRAM

DBP - Rev 6/93

U120

U114

N80C196KB-12

U115

U123

Y1

29

L1

JC

R713
R712

R119

T1T2

R802

U116

U5

U130

U25

U22

U109

R566

U108

JP

JR

U102

R504
R505

U10

U17

R705

506
507

518
519

U18

C300

513

C313

C312

DS

1

2

3

4

U101

U100

C139

U103

U106

ON

5

6

7

8

9

OFF

U7

R500
R501

R502

R503
R508

R509
R510
R511

R708

706
704

U28

JE

R R

R
1 234 5 6 7

C1C2

R800

U31

U107

R707

U27

R R R R

U21

U9 U21

U11

D7

U112

U113

U26

U29

HC
HB
HA

U20

JPR

U8

DCB COMPONENTS LAYOUT

DBP - Rev 6/93